Tighten Sort Unsorted matching; consolidate file management tools

Fix Sort Unsorted picking a wrong destination on words that are common
clutter across many categories (a creator's name, generic marketing
filler) by ranking matches on a folder's own deliberate name over
incidental sibling-course words, and downweighting borrowed words that
recur across many categories. Add a folder-picker/create-new/rename UI
to override any proposal.

Turn /unsorted into a general File Management page: move Refresh
Library, Bulk Rename, and Manage Library (hide/rename) here from
Settings, add a Move action to Manage Library using the same picker,
and add Duplicate Courses and Clean Up Stale References tools. Add a
footer link to the page from the dashboard.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -88,19 +88,52 @@ silently stay blank instead of erroring.
 - Cover art: uses a manually-placed `cover`/`folder`/`thumbnail`/`thumb`/
   `poster` image if a course has one, otherwise auto-generates one via
   `ffmpeg` from a frame of the course's first video
-- Hide courses/folders from the browser without touching anything on disk;
+- **File Management** ([/unsorted](templates/unsorted.html), linked from
-  bulk-select to hide or queue several at once
+  Settings and from a footer link on the dashboard): a dedicated page for
-- Bulk rename across course/folder names (find & replace)
+  everything that touches files on disk, since it needs more room than a
-- **Sort Unsorted** ([/unsorted](templates/unsorted.html), linked from
+  Settings card and warrants review before anything actually changes.
-  Settings): drop new/incoming courses into an `Unsorted` folder at the
+  - *Sort Unsorted*: drop new/incoming courses into an `Unsorted` folder at
-  library root, then scan proposes a destination for each one by keyword
+  the library root, then scan proposes a destination for each one by keyword
   overlap against the *existing* category tree - read fresh from disk every
   scan, so it adapts to whatever folders you actually have rather than any
   hardcoded subject list. Three outcomes per item: a confident match to an
   existing folder, a suggested new subfolder under a broader category match,
   or "needs review" (unchecked by default) when nothing overlaps at all.
-  Every destination is editable before applying, and nothing on disk moves
+  Every row has a folder-picker dropdown (listing every real category in the
-  until you review and hit Apply.
+  library, plus "+ Create new folder…" to type a brand-new path) so a wrong
+  or low-confidence guess is one click to correct, and a name field to
+  rename the course's folder in the same move. Nothing on disk moves until
+  you review and hit Apply. Matching ignores common noise (e-learning
+  platform names, release/distribution-group tags, dates) via a stopword
+  list, and beyond that treats a match against a folder's own deliberate
+  name as always stronger evidence than a word only borrowed from a
+  sibling course's title - and among those borrowed words, downweights
+  ones that recur across many categories (a prolific creator's name, etc.)
+  so they can't outvote a genuinely specific word just by sharing more of
+  them.
+  - *Refresh Library*: manually bypasses the 5-minute filesystem-scan cache,
+  for when files were added/removed directly on disk.
+  - *Bulk Rename*: find & replace across every course/folder name in the
+  library at once, with a per-match preview and the ability to drop
+  individual matches before applying.
+  - *Manage Library*: hide courses/folders from the browser without
+  touching anything on disk (hiding a folder hides everything inside it;
+  bulk-select elsewhere to hide or queue several at once), rename a
+  course/folder in place, or **move** one anywhere else in the library via
+  the same folder-picker/create-new-folder UI Sort Unsorted uses - handy
+  for correcting a bad auto-sort later or just reorganizing.
+  - *Duplicate Courses*: scans every course in the library (Unsorted
+  included) for names that look like the same thing filed twice, using the
+  same tokenizer as Sort Unsorted so a platform-name or release-tag
+  difference doesn't hide a real duplicate. Groups by similarity (union of
+  any two courses over the threshold, transitively) rather than showing
+  raw pairs; each course in a group gets a one-click Hide.
+  - *Clean Up Stale References*: finds entries in the hidden-paths list,
+  Next Up queue, or Recently Viewed history that point at a path no longer
+  on disk - normally from renaming/moving/deleting a course directly on
+  the NAS instead of through the app (doing it through the app already
+  keeps these in sync). Review individually or clear them all at once;
+  course files themselves are never touched.
 
 **Dashboard**
 - Library-wide stats (courses, lessons completed, time watched, time
@@ -138,8 +171,8 @@ silently stay blank instead of erroring.
   actual color distance), or a fully custom accent color, corner radius,
   and card style
 - Font, text size, page width, and spacing density
-- Default library path override + manual "Refresh Library" (bypasses the
+- Default library path override (Refresh Library and Bulk Rename live on the
-  5-minute filesystem-scan cache)
+  File Management page - see above)
 
 **Backup & integrations**
 - One-click backup export and restore: settings, hidden-path choices, the

offlineu_core.py

@@ -1009,10 +1009,11 @@ def rebase_library_path(old_abs: str, new_abs: str) -> None:
     """
     After a directory in the library is renamed/moved on disk, rewrite any
     stored absolute paths that pointed inside it (hidden_paths.json,
-    recent_views.json's course_path) so curation and Recently Viewed don't
+    next_up.json, recent_views.json's course_path) so curation, the Next
-    silently go stale. Lesson-level progress needs no rebasing - it lives
+    Up queue, and Recently Viewed don't silently go stale. Lesson-level
-    inside the directory itself, keyed by paths relative to it, so it moves
+    progress needs no rebasing - it lives inside the directory itself,
-    with the rename automatically.
+    keyed by paths relative to it, so it moves with the rename
+    automatically.
     """
     hidden = get_hidden_paths()
     rebased_hidden = [_rebase_prefix(p, old_abs, new_abs) for p in hidden]
@@ -1021,6 +1022,11 @@ def rebase_library_path(old_abs: str, new_abs: str) -> None:
         with open(HIDDEN_PATHS_FILE, 'w') as f:
             json.dump(sorted(set(rebased_hidden)), f, indent=2)
 
+    queued = get_next_up_paths()
+    rebased_queue = [_rebase_prefix(p, old_abs, new_abs) for p in queued]
+    if rebased_queue != queued:
+        _save_next_up_paths(rebased_queue)
+
     views = get_recent_views()
     changed = False
     for entry in views:
@@ -1200,6 +1206,29 @@ _TOKEN_STOPWORDS = {
     'a', 'an', 'and', 'for', 'from', 'in', 'is', 'of', 'on', 'or', 'the', 'to', 'with',
     'course', 'courses', 'training', 'class', 'complete', 'full', 'guide', 'tutorial',
     'part', 'vol', 'volume', 'edition',
+    # Skill-level/marketing filler - describes the packaging, not the
+    # subject, same spirit as 'complete'/'guide'/'tutorial' above.
+    'advanced', 'intermediate', 'beginner', 'beginners', 'basics', 'basic',
+    'essentials', 'fundamentals', 'mastering', 'master', 'crash', 'level', 'levels',
+    # E-learning platforms/marketplaces - whichever site a course was bought
+    # or ripped from says nothing about its subject, and it shows up in
+    # almost every course name from that source.
+    'udemy', 'pluralsight', 'lynda', 'linkedin', 'linkedinlearning', 'coursera',
+    'skillshare', 'packt', 'packtpub', 'oreilly', 'edx', 'educative', 'egghead',
+    'frontendmasters', 'codecademy', 'udacity', 'skillsoft', 'cbtnuggets', 'cbt',
+    'itprotv', 'cybrary', 'tutsplus', 'masterclass', 'treehouse', 'datacamp',
+    # Scene/distribution-group tags and rip metadata that piggyback on
+    # downloaded course names - never a subject, always noise.
+    'bookware', 'tutsnode', 'ftu', 'ftuforum', 'freecoursesonline', 'freetutorials',
+    'coursedrive', 'downtem', 'glodls', 'garr', 'ridware', 'illiterate', 'zh',
+    'nfo', 'readnfo', 'repack', 'reup', 'reupload', 'repost', 'release', 'released',
+    'rip', 'x264', 'x265', 'www', 'com', 'net', 'org', 'info',
+    # "Freshness" marketing words - describe the release, not the subject.
+    'update', 'updated', 'new', 'newest', 'latest', 'final', 'retail',
+    # Calendar words - dates say nothing about what a course is about.
+    'january', 'february', 'march', 'april', 'june', 'july', 'august', 'september',
+    'october', 'november', 'december', 'jan', 'feb', 'mar', 'apr', 'jun', 'jul',
+    'aug', 'sep', 'sept', 'oct', 'nov', 'dec',
 }
 
 
@@ -1236,16 +1265,26 @@ def _tokenize_ordered(name: str) -> List[str]:
 def _build_category_index() -> List[Dict[str, Any]]:
     """
     Every category/subcategory folder currently in the library (e.g. IT,
-    IT/AWS) as a possible destination, each with keyword tokens from its
+    IT/AWS) as a possible destination, each with keyword tokens split into
-    own path components plus the titles of any courses already filed
+    two tiers of trust:
-    directly under it - that second part lets a folder match on subjects
+      - 'path_tokens': from the folder's own path components - a deliberate
-    its name alone doesn't mention (an "IT/AWS" folder full of courses
+        name the user chose, so a match here is always taken at face value.
-    titled "...Solutions Architect..." now also matches on "solutions" and
+      - 'bonus_tokens': from the titles of courses already filed directly
-    "architect"), without hardcoding any subject list. Stops recursing
+        under it - lets a folder match on subjects its name alone doesn't
-    into a folder once it reads as a course itself (_looks_like_course,
+        mention (an "IT/AWS" folder full of courses titled "...Solutions
-    the same rule the Library browser uses), so individual courses never
+        Architect..." now also matches on "solutions" and "architect"),
-    show up as if they were categories to file things under. The Unsorted
+        without hardcoding any subject list. Since these come from
-    folder itself is excluded - it's the source, never a valid destination.
+        whatever the courses happen to be named, they're incidental rather
+        than deliberate - _propose_destination downweights them by how
+        many *different* categories share the same bonus word, so a word
+        that turns out to be common clutter (recurring across many
+        categories' course titles) can't outweigh a specific match
+        elsewhere just by sharing more of it.
+    Stops recursing into a folder once it reads as a course itself
+    (_looks_like_course, the same rule the Library browser uses), so
+    individual courses never show up as if they were categories to file
+    things under. The Unsorted folder itself is excluded - it's the
+    source, never a valid destination.
     """
     library_root = Path(get_library_root())
     try:
@@ -1271,20 +1310,23 @@ def _build_category_index() -> List[Dict[str, Any]]:
             if _looks_like_course(entry):
                 continue
             new_parts = path_parts + [entry.name]
-            tokens: Set[str] = set()
+            path_tokens: Set[str] = set()
             for part in new_parts:
-                tokens |= _tokenize(part)
+                path_tokens |= _tokenize(part)
+            bonus_tokens: Set[str] = set()
             try:
                 for child in entry.iterdir():
                     if child.is_dir() and not child.name.startswith('.') and _looks_like_course(child):
-                        tokens |= _tokenize(child.name)
+                        bonus_tokens |= _tokenize(child.name)
             except (PermissionError, OSError):
                 pass
+            bonus_tokens -= path_tokens
             categories.append({
                 'path': str(entry),
                 'relative': '/'.join(new_parts),
                 'depth': len(new_parts),
-                'tokens': tokens,
+                'path_tokens': path_tokens,
+                'bonus_tokens': bonus_tokens,
             })
             walk(entry, new_parts)
 
@@ -1292,6 +1334,20 @@ def _build_category_index() -> List[Dict[str, Any]]:
     return categories
 
 
+def _bonus_token_frequency(categories: List[Dict[str, Any]]) -> Dict[str, int]:
+    """How many distinct categories each bonus token shows up in, across
+    the whole library - used to tell a word that's actually specific to one
+    place ("cloudformation") from one that's just common clutter recurring
+    in course titles everywhere ("advanced", a creator's name, etc.), so
+    the latter can be downweighted instead of needing to be individually
+    named as a stopword ahead of time."""
+    freq: Dict[str, int] = {}
+    for cat in categories:
+        for token in cat['bonus_tokens']:
+            freq[token] = freq.get(token, 0) + 1
+    return freq
+
+
 def _list_unsorted_items() -> List[Path]:
     """Direct children of the Unsorted folder - each one is a course
     waiting to be filed into the real category tree."""
@@ -1304,7 +1360,8 @@ def _list_unsorted_items() -> List[Path]:
     )
 
 
-def _propose_destination(item_name: str, categories: List[Dict[str, Any]]) -> Dict[str, Any]:
+def _propose_destination(item_name: str, categories: List[Dict[str, Any]],
+                          bonus_df: Dict[str, int]) -> Dict[str, Any]:
     """
     Best-effort destination for one Unsorted item, by keyword overlap
     against the existing category tree. Three outcomes:
@@ -1314,11 +1371,26 @@ def _propose_destination(item_name: str, categories: List[Dict[str, Any]]) -> Di
         named from whichever of the item's own keywords the category
         didn't already cover.
       - 'manual': nothing matches with any confidence - needs a human.
-    "Confident" here means either a fairly specific existing folder (2+
+    Categories are ranked by evidence quality, not raw shared-word count -
-    levels deep, e.g. IT/AWS) matched on even one shared keyword, or a
+    a match on a *path* token (the folder's own deliberate name, e.g. the
-    shallower folder matched on 2+ - a single shared word with a bare
+    "AWS" in IT/AWS) always outranks any number of *bonus* tokens (words
-    top-level category ("IT") isn't enough to drop something straight
+    only borrowed from a sibling course's title - see
-    into it; that's exactly the case a new subfolder proposal is for.
+    _build_category_index), since a folder's own name is deliberate and a
+    sibling course's title is incidental. Among bonus-only matches, the
+    single least-diluted word wins rather than the total - a bonus word
+    shared by only one category counts fully, one recurring across N
+    categories counts for 1/N - so several incidental, recurring words (a
+    prolific creator's name, a repeated marketing phrase, etc. showing up
+    across many categories' course titles) can't outvote one genuinely
+    specific word just by there being more of them, and don't need to be
+    individually named as stopwords ahead of time to be discounted.
+    "Confident" then means the best match is either a path-token hit or an
+    essentially-unique bonus word (not diluted across other categories),
+    AND it's either at a fairly specific existing folder (2+ levels deep,
+    e.g. IT/AWS) or corroborated by a second shared word - one weak,
+    common word alone isn't enough to drop something straight into a bare
+    top-level category ("IT"); that's exactly the case a new subfolder
+    proposal is for.
     """
     item_tokens_ordered = _tokenize_ordered(item_name)
     item_tokens = set(item_tokens_ordered)
@@ -1328,26 +1400,36 @@ def _propose_destination(item_name: str, categories: List[Dict[str, Any]]) -> Di
 
     scored = []
     for cat in categories:
-        overlap = item_tokens & cat['tokens']
+        overlap = item_tokens & (cat['path_tokens'] | cat['bonus_tokens'])
-        if overlap:
+        if not overlap:
-            scored.append((len(overlap), cat['depth'], cat, overlap))
+            continue
+        path_hits = overlap & cat['path_tokens']
+        bonus_overlap = overlap - cat['path_tokens']
+        bonus_best = max((1.0 / bonus_df.get(t, 1) for t in bonus_overlap), default=0.0)
+        scored.append({
+            'cat': cat, 'overlap': overlap,
+            'path_hits': len(path_hits), 'bonus_best': bonus_best, 'count': len(overlap),
+        })
 
     if not scored:
         return {'type': 'manual', 'destination': None,
                 'reason': "No existing folder shares any keywords with this name."}
 
-    scored.sort(key=lambda s: (s[0], s[1]), reverse=True)
+    scored.sort(key=lambda s: (s['path_hits'], s['bonus_best'], s['count'], s['cat']['depth']), reverse=True)
-    best_count, best_depth, best_cat, best_overlap = scored[0]
+    best = scored[0]
-    overlap_words = ', '.join(w for w in item_tokens_ordered if w in best_overlap)
+    best_cat = best['cat']
+    overlap_words = ', '.join(w for w in item_tokens_ordered if w in best['overlap'])
+    best_all_tokens = best_cat['path_tokens'] | best_cat['bonus_tokens']
 
-    if best_depth >= 2 or best_count >= 2:
+    is_strong_match = best['path_hits'] >= 1 or best['bonus_best'] >= 1.0
+    if is_strong_match and (best_cat['depth'] >= 2 or best['count'] >= 2):
         return {
             'type': 'existing',
             'destination': best_cat['relative'],
             'reason': f'Matches existing folder "{best_cat["relative"]}" on: {overlap_words}',
         }
 
-    leftover = item_tokens - best_cat['tokens']
+    leftover = item_tokens - best_all_tokens
     if leftover:
         # preserve the item's own word order rather than the set's
         # arbitrary one, so "Docker Compose Basics" suggests "Compose
@@ -1368,6 +1450,110 @@ def _propose_destination(item_name: str, categories: List[Dict[str, Any]]) -> Di
     }
 
 
+def _find_duplicate_courses(min_similarity: float = 0.6) -> List[Dict[str, Any]]:
+    """
+    Group courses across the whole library (Unsorted included, so a
+    just-dropped item that duplicates something already filed gets caught
+    too) whose names look like the same thing filed twice - a re-download
+    that landed in a different category, or a course that's both sorted
+    and still sitting in Unsorted. Reuses Sort Unsorted's own
+    tokenizer/stopword list, so platform names, release-group tags, and
+    dates are already ignored - "AWS Certified Solutions Architect" and
+    "AWS.Certified.Solutions.Architect.2024.BOOKWARE-XYZ" tokenize down to
+    the same core words despite looking nothing alike as strings.
+    Pairwise Jaccard similarity (shared tokens / all tokens) at or above
+    min_similarity gets union-found into groups, so if A matches B and B
+    matches C, all three land in one group instead of two overlapping
+    pairs. Nothing here touches disk - it's read-only, for the user to
+    review and hide/rename/move manually.
+    """
+    entries = []
+    for course in get_all_course_dirs():
+        tokens = _tokenize(course.name)
+        if tokens:
+            entries.append({'path': str(course), 'name': course.name, 'tokens': tokens})
+
+    n = len(entries)
+    parent = list(range(n))
+
+    def find(i: int) -> int:
+        while parent[i] != i:
+            parent[i] = parent[parent[i]]
+            i = parent[i]
+        return i
+
+    def union(i: int, j: int) -> None:
+        ri, rj = find(i), find(j)
+        if ri != rj:
+            parent[ri] = rj
+
+    pair_similarity: Dict[Tuple[int, int], float] = {}
+    for i in range(n):
+        for j in range(i + 1, n):
+            a, b = entries[i]['tokens'], entries[j]['tokens']
+            union_tokens = a | b
+            if not union_tokens:
+                continue
+            similarity = len(a & b) / len(union_tokens)
+            if similarity >= min_similarity:
+                pair_similarity[(i, j)] = similarity
+                union(i, j)
+
+    clusters: Dict[int, List[int]] = {}
+    for i in range(n):
+        clusters.setdefault(find(i), []).append(i)
+
+    groups = []
+    for members in clusters.values():
+        if len(members) < 2:
+            continue
+        best_similarity = max(
+            (sim for (i, j), sim in pair_similarity.items() if i in members and j in members),
+            default=0.0
+        )
+        groups.append({
+            'courses': sorted(
+                ({'path': entries[i]['path'], 'name': entries[i]['name']} for i in members),
+                key=lambda c: c['name'].lower()
+            ),
+            'similarity': round(best_similarity, 2),
+        })
+
+    groups.sort(key=lambda g: g['similarity'], reverse=True)
+    return groups
+
+
+def _find_stale_references() -> Dict[str, List[Dict[str, str]]]:
+    """
+    Entries in hidden_paths.json / next_up.json / recent_views.json that
+    point at a path no longer on disk - typically because a course was
+    renamed, moved, or deleted directly on the NAS rather than through the
+    app (a rename/move made through the app already rebases these, see
+    rebase_library_path). Read-only; nothing is removed until
+    /api/library/stale-references/clean is called with the exact items
+    reviewed here.
+    """
+    stale: Dict[str, List[Dict[str, str]]] = {'hidden': [], 'next_up': [], 'recent_views': []}
+
+    for path in get_hidden_paths():
+        if not os.path.isdir(path):
+            stale['hidden'].append({'path': path, 'name': os.path.basename(path.rstrip(os.sep)) or path})
+
+    for path in get_next_up_paths():
+        if not os.path.isdir(path):
+            stale['next_up'].append({'path': path, 'name': os.path.basename(path.rstrip(os.sep)) or path})
+
+    seen: Set[str] = set()
+    for entry in get_recent_views():
+        path = entry.get('course_path', '')
+        if path and path not in seen and not os.path.isdir(path):
+            seen.add(path)
+            name = entry.get('course_name') or os.path.basename(path.rstrip(os.sep)) or path
+            stale['recent_views'].append({'path': path, 'name': name})
+
+    return stale
+
+
 def _probe_media_duration_seconds(file_path: Path) -> Optional[float]:
     """Read a single media file's duration via ffprobe. None if ffprobe is
     missing, the file isn't readable, or the output can't be parsed."""
@@ -2045,6 +2231,20 @@ def get_recent_views() -> List[Dict[str, Any]]:
     return []
 
 
+def remove_recent_views_for_path(path: str) -> List[Dict[str, Any]]:
+    """Drop every Recently Viewed entry for one course path - there can be
+    several, one per lesson. Used to clear a stale reference left behind
+    when a course was deleted/moved outside the app."""
+    entries = get_recent_views()
+    normalized = os.path.abspath(path)
+    remaining = [e for e in entries if e.get('course_path') != normalized]
+    if remaining != entries:
+        os.makedirs(DATA_DIR, exist_ok=True)
+        with open(RECENT_VIEWS_FILE, 'w') as f:
+            json.dump(remaining, f, indent=2)
+    return remaining
+
+
 def _read_lesson_progress_entry(course_path: str, lesson_path: str) -> Dict[str, Any]:
     """
     Read a single lesson's progress entry directly from its course's own
@@ -2681,16 +2881,20 @@ def scan_unsorted_api():
 
     items = _list_unsorted_items()
     categories = _build_category_index()
+    bonus_df = _bonus_token_frequency(categories)
     results = []
     for item in items:
-        proposal = _propose_destination(item.name, categories)
+        proposal = _propose_destination(item.name, categories, bonus_df)
         results.append({'name': item.name, 'path': str(item), **proposal})
 
+    category_paths = sorted((c['relative'] for c in categories), key=str.lower)
+
     return jsonify({
         'items': results,
         'unsorted_exists': True,
         'unsorted_path': unsorted_root,
         'category_count': len(categories),
+        'categories': category_paths,
     })
 
 
@@ -2698,8 +2902,10 @@ def scan_unsorted_api():
 def apply_unsorted_api():
     """
     Move a batch of Unsorted items to their (possibly user-edited)
-    destinations, creating new subfolders as needed. Every source must
+    destinations, creating new subfolders as needed, and optionally renaming
-    actually be inside the Unsorted folder and every destination must
+    each item's folder in the same step (move + rename is one filesystem
+    operation either way, so there's no reason to make it two). Every source
+    must actually be inside the Unsorted folder and every destination must
     stay inside the library root and outside Unsorted itself - guards
     against a hand-edited destination path escaping the library, the same
     zip-slip-style check used for backup restore.
@@ -2738,9 +2944,16 @@ def apply_unsorted_api():
             errors.append({'source': source, 'error': 'Destination cannot be inside Unsorted'})
             continue
 
-        final_path = os.path.join(dest_dir, os.path.basename(source_abs))
+        final_name = ((move or {}).get('name') or '').strip()
+        if not final_name:
+            final_name = os.path.basename(source_abs)
+        if os.sep in final_name or (os.altsep and os.altsep in final_name) or final_name in ('.', '..'):
+            errors.append({'source': source, 'error': f'"{final_name}" is not a valid folder name'})
+            continue
+
+        final_path = os.path.join(dest_dir, final_name)
         if os.path.exists(final_path):
-            errors.append({'source': source, 'error': f'"{os.path.basename(source_abs)}" already exists at that destination'})
+            errors.append({'source': source, 'error': f'"{final_name}" already exists at that destination'})
             continue
 
         try:
@@ -2754,6 +2967,129 @@ def apply_unsorted_api():
     return jsonify({'success': True, 'moved': len(moved), 'errors': errors})
 
 
+@app.route('/api/library/categories')
+def library_categories_api():
+    """Every category/subcategory folder in the library, for destination
+    pickers - Sort Unsorted's own picker gets this from /api/unsorted/scan
+    already; this is the same list for callers (like Manage Library's move
+    action) that need it without depending on an Unsorted-folder scan."""
+    categories = _build_category_index()
+    return jsonify({'categories': sorted((c['relative'] for c in categories), key=str.lower)})
+
+
+@app.route('/api/library/move', methods=['POST'])
+def move_library_item_api():
+    """
+    Move (and optionally rename) any course or folder already in the
+    library to a different location - the general-purpose version of
+    /api/unsorted/apply, for reorganizing something already filed rather
+    than just-arrived. Same source/destination-inside-library-root safety
+    checks, plus one apply_unsorted_api doesn't need: the destination
+    can't be inside the source's own subtree, since here the source can
+    itself be a category folder with children, not just a leaf course.
+    """
+    data = request.json or {}
+    source = (data.get('source') or '').strip()
+    destination_relative = (data.get('destination') or '').strip().strip('/')
+    final_name = (data.get('name') or '').strip()
+
+    if not source or not destination_relative:
+        return jsonify({'success': False, 'error': 'Missing source or destination'}), 400
+
+    library_root = os.path.abspath(get_library_root())
+    source_abs = os.path.abspath(source)
+
+    if not (source_abs == library_root or source_abs.startswith(library_root + os.sep)):
+        return jsonify({'success': False, 'error': 'Source is outside the library'}), 403
+    if source_abs == library_root:
+        return jsonify({'success': False, 'error': 'Cannot move the library root itself'}), 400
+    if not os.path.isdir(source_abs):
+        return jsonify({'success': False, 'error': 'Source no longer exists'}), 404
+
+    dest_dir = os.path.abspath(os.path.join(library_root, destination_relative))
+    if not (dest_dir == library_root or dest_dir.startswith(library_root + os.sep)):
+        return jsonify({'success': False, 'error': 'Destination is outside the library'}), 403
+    if dest_dir == source_abs or dest_dir.startswith(source_abs + os.sep):
+        return jsonify({'success': False, 'error': 'Cannot move a folder into itself'}), 400
+
+    if not final_name:
+        final_name = os.path.basename(source_abs)
+    if os.sep in final_name or (os.altsep and os.altsep in final_name) or final_name in ('.', '..'):
+        return jsonify({'success': False, 'error': f'"{final_name}" is not a valid folder name'}), 400
+
+    final_path = os.path.join(dest_dir, final_name)
+    if final_path == source_abs:
+        return jsonify({'success': False, 'error': 'Already there'}), 400
+    if os.path.exists(final_path):
+        return jsonify({'success': False, 'error': f'"{final_name}" already exists at that destination'}), 409
+
+    try:
+        os.makedirs(dest_dir, exist_ok=True)
+        shutil.move(source_abs, final_path)
+    except OSError as e:
+        return jsonify({'success': False, 'error': str(e)}), 500
+
+    invalidate_cache()
+    rebase_library_path(source_abs, final_path)
+
+    global current_course
+    active_course_reset = False
+    if current_course is not None:
+        course_abs = os.path.abspath(current_course.path)
+        if course_abs == source_abs or course_abs.startswith(source_abs + os.sep):
+            current_course = None
+            active_course_reset = True
+
+    return jsonify({'success': True, 'new_path': final_path, 'active_course_reset': active_course_reset})
+
+
+@app.route('/api/library/duplicates')
+def duplicate_courses_api():
+    """Scan for courses that look like copies of each other by name (see
+    _find_duplicate_courses). Not run automatically like Sort Unsorted's
+    scan - it's O(n^2) over every course in the library, so it's a manual
+    trigger instead."""
+    groups = _find_duplicate_courses()
+    return jsonify({'groups': groups, 'course_count': len(get_all_course_dirs())})
+
+
+@app.route('/api/library/stale-references')
+def stale_references_api():
+    """Entries in hidden_paths/next_up/recent_views pointing at paths no
+    longer on disk (see _find_stale_references). Read-only - nothing is
+    removed until /api/library/stale-references/clean is called."""
+    return jsonify(_find_stale_references())
+
+
+@app.route('/api/library/stale-references/clean', methods=['POST'])
+def clean_stale_references_api():
+    """Remove specific stale entries the client reviewed via the scan
+    above. Re-checks each path still doesn't exist before removing it, in
+    case it became valid again between scan and apply."""
+    data = request.json or {}
+    items = data.get('items') or []
+    if not isinstance(items, list) or not items:
+        return jsonify({'success': False, 'error': 'No items provided'}), 400
+
+    removed = 0
+    for item in items:
+        category = (item or {}).get('category')
+        path = (item or {}).get('path')
+        if not path or os.path.isdir(path):
+            continue
+        if category == 'hidden':
+            set_path_hidden(path, False)
+            removed += 1
+        elif category == 'next_up':
+            set_path_queued(path, False)
+            removed += 1
+        elif category == 'recent_views':
+            remove_recent_views_for_path(path)
+            removed += 1
+
+    return jsonify({'success': True, 'removed': removed})
+
+
 # Single-process personal app, so a plain dict + background thread is
 # enough state for the duration prewarm - no job queue needed. Guarded by
 # 'running' so a second click while one's in flight just reports progress

templates/course_dashboard.html

@@ -197,6 +197,21 @@
             transform: translateY(0);
         }
 
+        .page-footer-link {
+            text-align: center;
+            padding: 24px 0 8px;
+        }
+        .page-footer-link a {
+            color: var(--text-muted);
+            text-decoration: none;
+            display: inline-flex;
+            align-items: center;
+            gap: 6px;
+            font-size: 0.85em;
+        }
+        .page-footer-link a:hover {
+            color: var(--accent);
+        }
         .bottom-tab-bar {
             position: fixed;
             left: 0;
@@ -1313,6 +1328,10 @@
         </div>
         {% endif %}
     {% endif %}
+
+    <div class="page-footer-link">
+        <a href="/unsorted">{{ icons.icon('folder', 14) }} File Management</a>
+    </div>
     </div>
 
     <nav class="bottom-tab-bar">

templates/settings.html

@@ -221,101 +221,6 @@
             padding: 5px 12px;
             font-size: 0.85em;
         }
-        .curate-row {
-            display: flex;
-            flex-wrap: wrap;
-            align-items: center;
-            justify-content: space-between;
-            gap: 10px;
-            padding: 8px 10px;
-            border-radius: var(--radius);
-            background: var(--bg-tertiary);
-            margin-bottom: 5px;
-            cursor: pointer;
-        }
-        .curate-row:hover {
-            background: var(--bg-tertiary-hover);
-        }
-        .curate-row.is-hidden {
-            opacity: 0.55;
-        }
-        .curate-row-name {
-            display: flex;
-            align-items: center;
-            gap: 8px;
-            flex: 1;
-            min-width: 0;
-        }
-        .curate-row-name span.name {
-            overflow: hidden;
-            text-overflow: ellipsis;
-            white-space: nowrap;
-        }
-        .curate-toggle {
-            font-size: 1.1em;
-            width: 18px;
-            text-align: center;
-            flex-shrink: 0;
-        }
-        .curate-children {
-            margin-left: 22px;
-            margin-top: 4px;
-            display: none;
-        }
-        .curate-children.expanded {
-            display: block;
-        }
-        .curate-empty-hint {
-            color: var(--text-muted);
-            font-size: 0.9em;
-            padding: 6px 0;
-        }
-        .curate-actions {
-            display: flex;
-            align-items: center;
-            gap: 6px;
-            flex-shrink: 0;
-        }
-        .curate-rename-input {
-            flex: 1;
-            min-width: 0;
-            background: var(--bg-primary);
-            color: var(--text-primary);
-            border: 1px solid var(--accent);
-            border-radius: var(--radius);
-            padding: 4px 8px;
-            font-size: 0.95em;
-            font-family: var(--font-family);
-        }
-        .curate-row-status {
-            flex-basis: 100%;
-            font-size: 0.8em;
-            color: var(--error);
-        }
-        .bulk-rename-row {
-            display: flex;
-            align-items: center;
-            justify-content: space-between;
-            gap: 10px;
-            padding: 8px 10px;
-            border-radius: var(--radius);
-            background: var(--bg-tertiary);
-            margin-bottom: 5px;
-        }
-        .bulk-rename-row-names {
-            flex: 1;
-            min-width: 0;
-            overflow-wrap: break-word;
-            word-break: break-word;
-        }
-        .bulk-rename-old {
-            color: var(--text-muted);
-            font-size: 0.9em;
-            text-decoration: line-through;
-        }
-        .bulk-rename-new {
-            color: var(--text-primary);
-        }
         #save-status {
             font-size: 0.9em;
             color: var(--success);
@@ -448,11 +353,6 @@
                     <button class="btn" onclick="saveLibraryPath()">Save</button>
                 </div>
                 <span id="library-path-status" style="font-size: 0.85em; min-height: 1.2em;"></span>
-                <div style="display: flex; align-items: center; gap: 10px;">
-                    <button class="btn btn-secondary btn-sm" onclick="refreshLibraryCache()">{{ icons.icon('refresh', 14) }} Refresh Library</button>
-                    <span id="library-refresh-status" style="font-size: 0.85em; color: var(--text-muted);"></span>
-                </div>
-                <span class="setting-desc">Courses are cached briefly for speed - use this after adding or removing files directly on disk if you don't want to wait a few minutes for it to notice.</span>
 
                 <div style="display: flex; align-items: center; gap: 10px; margin-top: 10px;">
                     <button class="btn btn-secondary btn-sm" id="prewarm-durations-btn" onclick="startDurationPrewarm()">{{ icons.icon('refresh', 14) }} Precompute Lengths &amp; Cover Art</button>
@@ -463,50 +363,14 @@
         </div>
 
         <div class="card">
-            <h2>Sort Unsorted Courses</h2>
+            <h2>File Management</h2>
             <p class="setting-desc" style="margin-bottom: 12px;">
-                Drop new courses in an "Unsorted" folder at the root of your library, then use this to
+                Sort new courses out of an "Unsorted" folder at the root of your library, refresh the
-                propose where each one belongs based on your existing folder structure - nothing moves
+                library cache, bulk-rename or move things around, hide courses, check for duplicates, and
-                until you review and confirm on its own page.
+                clean up stale references - all on its own page, with room to review before anything
+                changes on disk.
             </p>
-            <a class="btn btn-secondary" href="/unsorted">{{ icons.icon('folder', 14) }} Open Sorter</a>
+            <a class="btn btn-secondary" href="/unsorted">{{ icons.icon('folder', 14) }} Open File Management</a>
-        </div>
-
-        <div class="card">
-            <h2>Manage Library</h2>
-            <p class="setting-desc" style="margin-bottom: 12px;">
-                Hide courses or whole folders from the Library browser without touching anything on disk
-                (hiding a folder hides everything inside it), or rename a course/folder directly - no need
-                to go to the NAS.
-            </p>
-
-            <div id="hidden-list-wrap" style="margin-bottom: 15px; display: none;">
-                <div style="font-weight: 600; margin-bottom: 8px; font-size: 0.9em; color: var(--text-muted);">Currently hidden</div>
-                <div id="hidden-list"></div>
-            </div>
-
-            <div style="font-weight: 600; margin-bottom: 8px; font-size: 0.9em; color: var(--text-muted);">Browse</div>
-            <div id="curate-path-bar" style="color: var(--text-muted); font-size: 13px; margin-bottom: 8px;"></div>
-            <div id="curate-tree"></div>
-        </div>
-
-        <div class="card">
-            <h2>Bulk Rename</h2>
-            <p class="setting-desc" style="margin-bottom: 12px;">
-                Find and replace text across every course/folder name in the library at once - handy for
-                stripping a release-group suffix off a batch of downloads. Nothing changes until you apply.
-            </p>
-            <div style="display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 10px;">
-                <input type="text" id="bulk-rename-find" class="hex-input"
-                       style="flex: 1; min-width: 140px; width: auto; font-family: var(--font-family);"
-                       placeholder="Find (e.g. .BOOKWARE-LERNSTUF)">
-                <input type="text" id="bulk-rename-replace" class="hex-input"
-                       style="flex: 1; min-width: 140px; width: auto; font-family: var(--font-family);"
-                       placeholder="Replace with (blank to remove)">
-                <button class="btn" onclick="previewBulkRename()">Preview</button>
-            </div>
-            <div id="bulk-rename-status" style="font-size: 0.85em; min-height: 1.2em; margin-bottom: 8px;"></div>
-            <div id="bulk-rename-preview"></div>
         </div>
 
         <div class="card">
@@ -627,10 +491,6 @@
         // built dynamically here are kept in sync with the same path data
         // by hand.
         const ICON_SVGS = {
-            ban: '<svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="9"></circle><line x1="5.6" y1="5.6" x2="18.4" y2="18.4"></line></svg>',
-            'graduation-cap': '<svg class="icon" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M22 9 12 4 2 9l10 5 10-5Z"></path><path d="M6 11v5c0 1.4 2.7 2.5 6 2.5s6-1.1 6-2.5v-5"></path></svg>',
-            folder: '<svg class="icon" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M3 7a2 2 0 0 1 2-2h4l2 2h8a2 2 0 0 1 2 2v8a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2Z"></path></svg>',
-            pencil: '<svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M12 20h9"></path><path d="M16.5 3.5a2.12 2.12 0 0 1 3 3L7 19l-4 1 1-4Z"></path></svg>',
             check: '<svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="20 6 9 17 4 12"></polyline></svg>',
         };
 
@@ -682,309 +542,6 @@
             }
         });
 
-        // ---- Library curation: hide/show courses & folders ----
-        function loadHiddenList() {
-            fetch('/api/hidden-paths')
-                .then(r => r.json())
-                .then(data => {
-                    const wrap = document.getElementById('hidden-list-wrap');
-                    const list = document.getElementById('hidden-list');
-                    const items = data.hidden_paths || [];
-                    if (items.length === 0) {
-                        wrap.style.display = 'none';
-                        return;
-                    }
-                    wrap.style.display = 'block';
-                    list.innerHTML = items.map(item => `
-                        <div class="curate-row">
-                            <div class="curate-row-name">
-                                <span>${ICON_SVGS.ban}</span>
-                                <span class="name">${item.name}</span>
-                            </div>
-                            <button class="btn btn-secondary btn-sm" onclick="toggleHidden('${item.path.replace(/'/g, "\\'")}', false)">Show</button>
-                        </div>
-                    `).join('');
-                })
-                .catch(() => {});
-        }
-
-        function loadCurateLevel(path, container, isRoot) {
-            const url = path ? `/library/manage?path=${encodeURIComponent(path)}` : '/library/manage';
-            fetch(url)
-                .then(r => r.json())
-                .then(data => {
-                    if (isRoot) {
-                        document.getElementById('curate-path-bar').textContent = `Browsing ${data.library_path}`;
-                    }
-                    renderCurateLevel(data, container);
-                })
-                .catch(() => {
-                    container.innerHTML = '<p style="color:var(--error);">Could not reach the library scanner.</p>';
-                });
-        }
-
-        function renderCurateLevel(data, container) {
-            if (!data.items || data.items.length === 0) {
-                const reason = (data.errors && data.errors.length) ? data.errors.join(' ') : 'Nothing here.';
-                container.innerHTML = `<div class="curate-empty-hint">${reason}</div>`;
-                return;
-            }
-            container.innerHTML = data.items.map(item => {
-                const safePath = item.path.replace(/'/g, "\\'");
-                const safeName = item.name.replace(/'/g, "\\'");
-                const icon = item.type === 'course' ? ICON_SVGS['graduation-cap'] : ICON_SVGS.folder;
-                const hiddenClass = item.hidden ? 'is-hidden' : '';
-                const renameBtn = `<button class="btn btn-secondary btn-sm" onclick="event.stopPropagation(); startRename(this, '${safePath}', '${safeName}')" title="Rename">${ICON_SVGS.pencil}</button>`;
-                const toggleBtn = `<button class="btn btn-secondary btn-sm" onclick="event.stopPropagation(); toggleHidden('${safePath}', ${!item.hidden}, this)">${item.hidden ? 'Show' : 'Hide'}</button>`;
-                const actions = `<div class="curate-actions">${renameBtn}${toggleBtn}</div>`;
-
-                if (item.type === 'course') {
-                    return `
-                        <div class="curate-row ${hiddenClass}">
-                            <div class="curate-row-name">
-                                <span>${icon}</span>
-                                <span class="name">${item.name}</span>
-                            </div>
-                            ${actions}
-                        </div>
-                    `;
-                }
-                return `
-                    <div class="curate-row ${hiddenClass}" onclick="toggleCurateDir(this, '${safePath}')">
-                        <div class="curate-row-name">
-                            <span class="curate-toggle">▶</span>
-                            <span>${icon}</span>
-                            <span class="name">${item.name}</span>
-                        </div>
-                        ${actions}
-                    </div>
-                    <div class="curate-children" data-loaded="false"></div>
-                `;
-            }).join('');
-        }
-
-        function toggleCurateDir(rowEl, path) {
-            const content = rowEl.nextElementSibling;
-            const toggleIcon = rowEl.querySelector('.curate-toggle');
-            if (!content || !content.classList.contains('curate-children')) return;
-
-            if (content.classList.contains('expanded')) {
-                content.classList.remove('expanded');
-                if (toggleIcon) toggleIcon.textContent = '▶';
-                return;
-            }
-            content.classList.add('expanded');
-            if (toggleIcon) toggleIcon.textContent = '▼';
-
-            if (content.dataset.loaded === 'true') return;
-            content.innerHTML = '<div class="curate-empty-hint">Loading...</div>';
-            content.dataset.loaded = 'true';
-            content.dataset.path = path;
-            loadCurateLevel(path, content, false);
-        }
-
-        function toggleHidden(path, hidden, btnEl) {
-            fetch('/api/hidden-paths', {
-                method: 'POST',
-                headers: { 'Content-Type': 'application/json' },
-                body: JSON.stringify({ path: path, hidden: hidden })
-            })
-            .then(r => r.json())
-            .then(data => {
-                if (data.success) {
-                    loadHiddenList();
-                    // Refresh just the level this toggle happened in, rather
-                    // than collapsing the whole tree back to root.
-                    const container = btnEl ? (btnEl.closest('.curate-children') || document.getElementById('curate-tree'))
-                                             : document.getElementById('curate-tree');
-                    const isRootContainer = container.id === 'curate-tree';
-                    const refreshPath = isRootContainer ? null : container.dataset.path;
-                    loadCurateLevel(refreshPath, container, isRootContainer);
-                }
-            })
-            .catch(() => {});
-        }
-
-        // ---- Library curation: rename a course/folder in place on disk ----
-        function startRename(btnEl, path, currentName) {
-            const row = btnEl.closest('.curate-row');
-            const nameSpan = row ? row.querySelector('.curate-row-name .name') : null;
-            if (!row || !nameSpan) return;
-
-            let settled = false;
-            const input = document.createElement('input');
-            input.type = 'text';
-            input.className = 'curate-rename-input';
-            input.value = currentName;
-            input.onclick = (e) => e.stopPropagation();
-            nameSpan.replaceWith(input);
-            input.focus();
-            input.select();
-
-            function cancel() {
-                if (settled) return;
-                settled = true;
-                input.replaceWith(nameSpan);
-            }
-            function commit() {
-                if (settled) return;
-                const newName = input.value.trim();
-                if (!newName || newName === currentName) {
-                    cancel();
-                    return;
-                }
-                settled = true;
-                submitRename(btnEl, path, newName, row, nameSpan, input);
-            }
-            input.addEventListener('keydown', (e) => {
-                e.stopPropagation();
-                if (e.key === 'Enter') { e.preventDefault(); commit(); }
-                else if (e.key === 'Escape') { e.preventDefault(); cancel(); }
-            });
-            input.addEventListener('blur', commit);
-        }
-
-        function submitRename(btnEl, path, newName, row, nameSpan, input) {
-            fetch('/api/rename-path', {
-                method: 'POST',
-                headers: { 'Content-Type': 'application/json' },
-                body: JSON.stringify({ path: path, new_name: newName })
-            })
-            .then(r => r.json().then(data => ({ ok: r.ok, data })))
-            .then(({ ok, data }) => {
-                if (!ok || !data.success) {
-                    input.replaceWith(nameSpan); // nameSpan still shows the original, unchanged name
-                    showRowError(row, data.error || 'Rename failed');
-                    return;
-                }
-                if (data.active_course_reset) {
-                    alert('That was your active course - reload the main page to pick it up under its new name.');
-                }
-                loadHiddenList();
-                const container = btnEl.closest('.curate-children') || document.getElementById('curate-tree');
-                const isRootContainer = container.id === 'curate-tree';
-                const refreshPath = isRootContainer ? null : container.dataset.path;
-                loadCurateLevel(refreshPath, container, isRootContainer);
-            })
-            .catch(() => {
-                input.replaceWith(nameSpan);
-                showRowError(row, 'Could not reach the server');
-            });
-        }
-
-        function showRowError(row, message) {
-            let status = row.querySelector('.curate-row-status');
-            if (!status) {
-                status = document.createElement('div');
-                status.className = 'curate-row-status';
-                row.appendChild(status);
-            }
-            status.textContent = message;
-        }
-
-        loadHiddenList();
-        loadCurateLevel(null, document.getElementById('curate-tree'), true);
-
-        // ---- Bulk rename: find/replace across every course/folder name ----
-        let bulkRenameMatches = [];
-
-        function previewBulkRename() {
-            const pattern = document.getElementById('bulk-rename-find').value;
-            const replacement = document.getElementById('bulk-rename-replace').value;
-            const status = document.getElementById('bulk-rename-status');
-            const preview = document.getElementById('bulk-rename-preview');
-            preview.innerHTML = '';
-            if (!pattern) {
-                status.style.color = 'var(--error)';
-                status.textContent = 'Enter text to find first.';
-                return;
-            }
-            status.style.color = 'var(--text-muted)';
-            status.textContent = 'Searching...';
-            fetch(`/api/bulk-rename/preview?pattern=${encodeURIComponent(pattern)}&replacement=${encodeURIComponent(replacement)}`)
-                .then(r => r.json())
-                .then(data => {
-                    bulkRenameMatches = data.matches || [];
-                    renderBulkRenamePreview();
-                })
-                .catch(() => {
-                    status.style.color = 'var(--error)';
-                    status.textContent = 'Could not reach the server.';
-                });
-        }
-
-        function renderBulkRenamePreview() {
-            const status = document.getElementById('bulk-rename-status');
-            const preview = document.getElementById('bulk-rename-preview');
-            if (bulkRenameMatches.length === 0) {
-                status.style.color = 'var(--text-muted)';
-                status.textContent = 'No matches.';
-                preview.innerHTML = '';
-                return;
-            }
-            status.textContent = '';
-            const rows = bulkRenameMatches.map((m, i) => `
-                <div class="bulk-rename-row">
-                    <div class="bulk-rename-row-names">
-                        <div class="bulk-rename-old">${m.old_name}</div>
-                        <div class="bulk-rename-new">→ ${m.new_name}</div>
-                    </div>
-                    <button class="btn btn-secondary btn-sm" onclick="removeBulkRenameMatch(${i})">Remove</button>
-                </div>
-            `).join('');
-            const count = bulkRenameMatches.length;
-            preview.innerHTML = rows +
-                `<button class="btn" style="margin-top: 10px;" onclick="applyBulkRename()">Apply ${count} Rename${count === 1 ? '' : 's'}</button>`;
-        }
-
-        function removeBulkRenameMatch(index) {
-            bulkRenameMatches.splice(index, 1);
-            renderBulkRenamePreview();
-        }
-
-        function applyBulkRename() {
-            if (!confirm(`Rename ${bulkRenameMatches.length} item(s)? This changes real folders on disk.`)) return;
-            const status = document.getElementById('bulk-rename-status');
-            status.style.color = 'var(--text-muted)';
-            status.textContent = 'Applying...';
-            fetch('/api/bulk-rename/apply', {
-                method: 'POST',
-                headers: { 'Content-Type': 'application/json' },
-                body: JSON.stringify({ items: bulkRenameMatches })
-            })
-            .then(r => r.json())
-            .then(data => {
-                const results = data.results || [];
-                const succeeded = results.filter(r => r.success).length;
-                const failed = results.filter(r => !r.success);
-                const activeCourseReset = results.some(r => r.active_course_reset);
-
-                status.style.color = failed.length ? 'var(--error)' : 'var(--success)';
-                let message = `${succeeded} renamed`;
-                if (failed.length) {
-                    message += `, ${failed.length} failed: ` +
-                        failed.map(f => `${f.old_name} (${f.error})`).join('; ');
-                } else {
-                    message += '.';
-                }
-                if (activeCourseReset) {
-                    message += ' Your active course was renamed - reload the main page to pick it up under its new name.';
-                }
-                status.textContent = message;
-
-                bulkRenameMatches = [];
-                document.getElementById('bulk-rename-preview').innerHTML = '';
-                document.getElementById('bulk-rename-find').value = '';
-                document.getElementById('bulk-rename-replace').value = '';
-                loadHiddenList();
-                loadCurateLevel(null, document.getElementById('curate-tree'), true);
-            })
-            .catch(() => {
-                status.style.color = 'var(--error)';
-                status.textContent = 'Could not reach the server.';
-            });
-        }
-
         function saveLibraryPath() {
             const input = document.getElementById('library_path');
             const status = document.getElementById('library-path-status');
@@ -1010,23 +567,6 @@
             });
         }
 
-        function refreshLibraryCache() {
-            const status = document.getElementById('library-refresh-status');
-            status.style.color = 'var(--text-muted)';
-            status.textContent = 'Refreshing…';
-            fetch('/api/library/refresh', { method: 'POST' })
-                .then(r => r.json())
-                .then(data => {
-                    status.style.color = data.success ? 'var(--success)' : 'var(--error)';
-                    status.innerHTML = data.success ? (ICON_SVGS.check + ' Refreshed') : 'Could not refresh';
-                    if (data.success) setTimeout(() => { status.textContent = ''; }, 3000);
-                })
-                .catch(() => {
-                    status.style.color = 'var(--error)';
-                    status.textContent = 'Could not reach the server';
-                });
-        }
-
         function updatePrewarmStatus(data) {
             const btn = document.getElementById('prewarm-durations-btn');
             const status = document.getElementById('prewarm-durations-status');

templates/unsorted.html

@@ -4,7 +4,7 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Sort Unsorted - OfflineU</title>
+    <title>File Management - OfflineU</title>
     <link rel="manifest" href="/static/manifest.json">
     <meta name="theme-color" content="#007acc">
     <link rel="apple-touch-icon" href="/static/icons/icon-192.png">
@@ -103,6 +103,179 @@
             padding: 20px 25px;
             margin-bottom: 20px;
         }
+        .section-title {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            font-size: 1.15em;
+            color: var(--text-primary);
+            margin: 34px 0 6px;
+        }
+        .section-title:first-of-type { margin-top: 0; }
+        .section-desc {
+            color: var(--text-muted);
+            font-size: 0.92em;
+            margin: 0 0 14px;
+        }
+        .text-input {
+            flex: 1;
+            min-width: 160px;
+            background: var(--bg-primary);
+            color: var(--text-primary);
+            border: 1px solid var(--border-color);
+            border-radius: var(--radius);
+            padding: 8px 10px;
+            font-size: 0.9em;
+            font-family: var(--font-family);
+        }
+        .bulk-rename-row {
+            display: flex;
+            align-items: center;
+            justify-content: space-between;
+            gap: 10px;
+            padding: 8px 10px;
+            border-radius: var(--radius);
+            background: var(--bg-tertiary);
+            margin-bottom: 5px;
+        }
+        .bulk-rename-row-names {
+            flex: 1;
+            min-width: 0;
+            overflow-wrap: break-word;
+            word-break: break-word;
+        }
+        .bulk-rename-old {
+            color: var(--text-muted);
+            font-size: 0.9em;
+            text-decoration: line-through;
+        }
+        .bulk-rename-new {
+            color: var(--text-primary);
+        }
+        .curate-row {
+            display: flex;
+            flex-wrap: wrap;
+            align-items: center;
+            justify-content: space-between;
+            gap: 10px;
+            padding: 8px 10px;
+            border-radius: var(--radius);
+            background: var(--bg-tertiary);
+            margin-bottom: 5px;
+            cursor: pointer;
+        }
+        .curate-row:hover {
+            background: var(--bg-tertiary-hover);
+        }
+        .curate-row.is-hidden {
+            opacity: 0.55;
+        }
+        .curate-row-name {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            flex: 1;
+            min-width: 0;
+        }
+        .curate-row-name span.name {
+            overflow: hidden;
+            text-overflow: ellipsis;
+            white-space: nowrap;
+        }
+        .curate-toggle {
+            font-size: 1.1em;
+            width: 18px;
+            text-align: center;
+            flex-shrink: 0;
+        }
+        .curate-children {
+            margin-left: 22px;
+            margin-top: 4px;
+            display: none;
+        }
+        .curate-children.expanded {
+            display: block;
+        }
+        .curate-empty-hint {
+            color: var(--text-muted);
+            font-size: 0.9em;
+            padding: 6px 0;
+        }
+        .curate-actions {
+            display: flex;
+            align-items: center;
+            gap: 6px;
+            flex-shrink: 0;
+        }
+        .curate-rename-input {
+            flex: 1;
+            min-width: 0;
+            background: var(--bg-primary);
+            color: var(--text-primary);
+            border: 1px solid var(--accent);
+            border-radius: var(--radius);
+            padding: 4px 8px;
+            font-size: 0.95em;
+            font-family: var(--font-family);
+        }
+        .curate-row-status {
+            flex-basis: 100%;
+            font-size: 0.8em;
+            color: var(--error);
+        }
+        .curate-move-panel {
+            background: var(--bg-tertiary);
+            border: 1px solid var(--accent);
+            border-radius: var(--radius);
+            padding: 12px 14px;
+            margin: -3px 0 8px 0;
+        }
+        .curate-move-actions {
+            display: flex;
+            gap: 8px;
+            margin-top: 10px;
+        }
+        .curate-move-status {
+            font-size: 0.82em;
+            margin-top: 6px;
+            min-height: 1.1em;
+        }
+        .dup-group {
+            background: var(--bg-tertiary);
+            border-radius: var(--radius);
+            padding: 12px 14px;
+            margin-bottom: 10px;
+        }
+        .dup-group-header {
+            font-size: 0.78em;
+            font-weight: 600;
+            text-transform: uppercase;
+            letter-spacing: 0.3px;
+            color: var(--accent);
+            margin-bottom: 8px;
+        }
+        .dup-course-row {
+            display: flex;
+            flex-wrap: wrap;
+            align-items: center;
+            gap: 10px;
+            padding: 6px 0;
+            border-top: 1px solid var(--border-color);
+        }
+        .dup-course-row:first-of-type {
+            border-top: none;
+        }
+        .dup-course-name {
+            font-weight: 600;
+        }
+        .dup-course-path {
+            flex: 1;
+            min-width: 160px;
+            color: var(--text-muted);
+            font-size: 0.8em;
+            overflow-wrap: break-word;
+            word-break: break-word;
+        }
         .toolbar {
             display: flex;
             align-items: center;
@@ -188,15 +361,27 @@
             color: var(--text-muted);
             margin-top: 4px;
         }
-        .sort-row-dest {
+        .sort-row-fields {
             display: flex;
-            align-items: center;
+            flex-wrap: wrap;
-            gap: 8px;
+            gap: 14px;
-            flex: 1;
+            margin-top: 10px;
-            min-width: 240px;
         }
-        .sort-row-dest input {
+        .sort-field {
             flex: 1;
+            min-width: 200px;
+            display: flex;
+            flex-direction: column;
+            gap: 5px;
+        }
+        .sort-field label {
+            font-size: 0.72em;
+            text-transform: uppercase;
+            letter-spacing: 0.3px;
+            color: var(--text-muted);
+        }
+        .sort-field input,
+        .sort-field select {
             background: var(--bg-primary);
             color: var(--text-primary);
             border: 1px solid var(--border-color);
@@ -204,9 +389,18 @@
             padding: 8px 10px;
             font-size: 0.9em;
             font-family: var(--font-family);
+            width: 100%;
         }
-        .sort-row-dest input:invalid,
+        .dest-picker {
-        .sort-row-dest input.empty {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+        }
+        .dest-picker select { flex: 1; }
+        .dest-new-input {
+            margin-top: 6px;
+        }
+        .dest-new-input.empty {
             border-color: var(--error);
         }
         .action-bar {
@@ -269,8 +463,11 @@
 
     <div class="page-content">
     <div class="container">
-        <h1>{{ icons.icon('folder', 24) }} Sort Unsorted</h1>
+        <h1>{{ icons.icon('folder', 24) }} File Management</h1>
-        <p class="subtitle">Propose a destination for every course sitting in the <strong>Unsorted</strong> folder, based on your existing category structure. Nothing moves until you apply it.</p>
+        <p class="subtitle">Sort new courses, refresh the library cache, bulk-rename, hide/move/rename anything already filed, check for duplicates, and clean up stale references. Nothing changes on disk until you review and apply it.</p>
+
+        <h2 class="section-title">{{ icons.icon('folder', 18) }} Sort Unsorted</h2>
+        <p class="section-desc">Propose a destination for every course sitting in the <strong>Unsorted</strong> folder, based on your existing category structure.</p>
 
         <div class="card">
             <div class="toolbar">
@@ -295,6 +492,60 @@
         </div>
 
         <div id="empty-state" class="empty-hint" style="display: none;"></div>
+
+        <h2 class="section-title">{{ icons.icon('refresh', 18) }} Refresh Library</h2>
+        <p class="section-desc">Courses are cached briefly for speed - use this after adding or removing files directly on disk if you don't want to wait a few minutes for it to notice.</p>
+        <div class="card">
+            <div class="toolbar">
+                <button class="btn btn-secondary" id="refresh-library-btn" onclick="refreshLibraryCache()">{{ icons.icon('refresh', 14) }} Refresh Library</button>
+                <span id="library-refresh-status" style="font-size: 0.85em; color: var(--text-muted);"></span>
+            </div>
+        </div>
+
+        <h2 class="section-title">{{ icons.icon('pencil', 18) }} Bulk Rename</h2>
+        <p class="section-desc">Find and replace text across every course/folder name in the library at once - handy for stripping a release-group suffix off a batch of downloads.</p>
+        <div class="card">
+            <div class="toolbar" style="margin-bottom: 10px;">
+                <input type="text" id="bulk-rename-find" class="text-input" placeholder="Find (e.g. .BOOKWARE-LERNSTUF)">
+                <input type="text" id="bulk-rename-replace" class="text-input" placeholder="Replace with (blank to remove)">
+                <button class="btn" onclick="previewBulkRename()">Preview</button>
+            </div>
+            <div id="bulk-rename-status" style="font-size: 0.85em; min-height: 1.2em; margin-bottom: 8px;"></div>
+            <div id="bulk-rename-preview"></div>
+        </div>
+
+        <h2 class="section-title">{{ icons.icon('folder', 18) }} Manage Library</h2>
+        <p class="section-desc">Hide courses or whole folders from the Library browser without touching anything on disk (hiding a folder hides everything inside it), or rename/move a course or folder directly - no need to go to the NAS.</p>
+        <div class="card">
+            <div id="hidden-list-wrap" style="margin-bottom: 15px; display: none;">
+                <div style="font-weight: 600; margin-bottom: 8px; font-size: 0.9em; color: var(--text-muted);">Currently hidden</div>
+                <div id="hidden-list"></div>
+            </div>
+
+            <div style="font-weight: 600; margin-bottom: 8px; font-size: 0.9em; color: var(--text-muted);">Browse</div>
+            <div id="curate-path-bar" style="color: var(--text-muted); font-size: 13px; margin-bottom: 8px;"></div>
+            <div id="curate-tree"></div>
+        </div>
+
+        <h2 class="section-title">{{ icons.icon('clipboard', 18) }} Duplicate Courses</h2>
+        <p class="section-desc">Scan for courses that look like the same thing filed twice - a re-download that landed in a different folder, or something that's both sorted and still sitting in Unsorted. Matching reuses the same tokenizer as Sort Unsorted, so platform names and release-group tags don't throw it off.</p>
+        <div class="card">
+            <div class="toolbar">
+                <button class="btn btn-secondary" id="dup-scan-btn" onclick="scanDuplicates()">{{ icons.icon('refresh', 14) }} Scan for Duplicates</button>
+                <span id="dup-status"></span>
+            </div>
+            <div id="dup-results"></div>
+        </div>
+
+        <h2 class="section-title">{{ icons.icon('trash', 18) }} Clean Up Stale References</h2>
+        <p class="section-desc">Renaming, moving, or deleting a course directly on the NAS (instead of through this app) can leave behind references in Hidden, Next Up, or Recently Viewed that point at nothing. Review and remove them here - course files on disk are never touched.</p>
+        <div class="card">
+            <div class="toolbar">
+                <button class="btn btn-secondary" id="stale-scan-btn" onclick="scanStaleReferences()">{{ icons.icon('refresh', 14) }} Scan for Stale References</button>
+                <span id="stale-status"></span>
+            </div>
+            <div id="stale-results"></div>
+        </div>
     </div>
     </div>
 
@@ -319,9 +570,15 @@
         // template literals can't call the Jinja macro.
         const ICON_SVGS = {
             folder: '<svg class="icon" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M3 7a2 2 0 0 1 2-2h4l2 2h8a2 2 0 0 1 2 2v8a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2Z"></path></svg>',
+            check: '<svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><polyline points="20 6 9 17 4 12"></polyline></svg>',
+            ban: '<svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><circle cx="12" cy="12" r="9"></circle><line x1="5.6" y1="5.6" x2="18.4" y2="18.4"></line></svg>',
+            'graduation-cap': '<svg class="icon" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M22 9 12 4 2 9l10 5 10-5Z"></path><path d="M6 11v5c0 1.4 2.7 2.5 6 2.5s6-1.1 6-2.5v-5"></path></svg>',
+            pencil: '<svg class="icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M12 20h9"></path><path d="M16.5 3.5a2.12 2.12 0 0 1 3 3L7 19l-4 1 1-4Z"></path></svg>',
         };
 
         let lastItems = [];
+        let lastCategories = [];
+        const NEW_FOLDER_VALUE = '__new__';
 
         function badgeLabel(type) {
             if (type === 'existing') return 'Existing folder';
@@ -336,11 +593,36 @@
             return String(text).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
         }
 
+        function categoryOptionsHtml() {
+            return lastCategories.map(path =>
+                `<option value="${escapeAttr(path)}">${escapeHtml(path.split('/').join(' / '))}</option>`
+            ).join('');
+        }
+
+        // Shared across Sort Unsorted's own picker and Manage Library's Move
+        // panel, so both work the same regardless of whether the Unsorted
+        // folder exists (Sort Unsorted's own scan skips categories entirely
+        // when there's nothing to sort).
+        function loadCategories() {
+            return fetch('/api/library/categories')
+                .then(r => r.json())
+                .then(data => { lastCategories = data.categories || []; })
+                .catch(() => {});
+        }
+
         function renderRows(items) {
             const container = document.getElementById('sort-rows');
+            const optionsHtml = categoryOptionsHtml();
+
             container.innerHTML = items.map((item, idx) => {
                 const checked = item.type !== 'manual' ? 'checked' : '';
                 const destValue = item.destination || '';
+                // An 'existing' proposal always names a real folder already in
+                // lastCategories, so it's the only case the <select> can point
+                // straight at; 'new_folder' and 'manual' (and any hand-edited
+                // destination that no longer matches a real folder) fall back
+                // to the "create new" option with the free-text path exposed.
+                const isNew = item.type !== 'existing' || !lastCategories.includes(destValue);
                 return `
                 <div class="sort-row" data-idx="${idx}">
                     <input type="checkbox" class="sort-row-check" ${checked}>
@@ -350,15 +632,40 @@
                             <span class="sort-badge ${item.type}">${badgeLabel(item.type)}</span>
                         </div>
                         <div class="sort-row-reason">${escapeHtml(item.reason || '')}</div>
+                        <div class="sort-row-fields">
+                            <div class="sort-field">
+                                <label>Folder name</label>
+                                <input type="text" class="rename-input" value="${escapeAttr(item.name)}">
                             </div>
-                    <div class="sort-row-dest">
+                            <div class="sort-field">
+                                <label>Destination folder</label>
+                                <div class="dest-picker">
                                     ${ICON_SVGS.folder}
-                        <input type="text" class="dest-input ${destValue ? '' : 'empty'}" value="${escapeAttr(destValue)}" placeholder="e.g. IT/AWS">
+                                    <select class="dest-select" data-initial="${escapeAttr(isNew ? NEW_FOLDER_VALUE : destValue)}">
+                                        ${optionsHtml}
+                                        <option value="${NEW_FOLDER_VALUE}">+ Create new folder…</option>
+                                    </select>
+                                </div>
+                                <input type="text" class="dest-new-input ${isNew && !destValue ? 'empty' : ''}"
+                                       style="display: ${isNew ? 'block' : 'none'};"
+                                       value="${escapeAttr(isNew ? destValue : '')}" placeholder="e.g. IT/NewCategory">
+                            </div>
+                        </div>
                     </div>
                 </div>`;
             }).join('');
 
-            container.querySelectorAll('.dest-input').forEach(input => {
+            container.querySelectorAll('.dest-select').forEach(select => {
+                select.value = select.dataset.initial;
+                const row = select.closest('.sort-row');
+                const newInput = row.querySelector('.dest-new-input');
+                select.addEventListener('change', () => {
+                    const showNew = select.value === NEW_FOLDER_VALUE;
+                    newInput.style.display = showNew ? 'block' : 'none';
+                    if (showNew) newInput.focus();
+                });
+            });
+            container.querySelectorAll('.dest-new-input').forEach(input => {
                 input.addEventListener('input', () => {
                     input.classList.toggle('empty', input.value.trim() === '');
                 });
@@ -418,14 +725,18 @@
                 if (!checkbox.checked) return;
                 const idx = parseInt(row.dataset.idx, 10);
                 const item = lastItems[idx];
-                const destInput = row.querySelector('.dest-input');
+                const select = row.querySelector('.dest-select');
-                const destination = destInput.value.trim();
+                const newInput = row.querySelector('.dest-new-input');
+                const renameInput = row.querySelector('.rename-input');
+                const usingNew = select.value === NEW_FOLDER_VALUE;
+                const destination = (usingNew ? newInput.value : select.value).trim();
+                const name = renameInput.value.trim();
                 if (!destination) {
                     skippedEmpty.push(item.name);
-                    destInput.classList.add('empty');
+                    if (usingNew) newInput.classList.add('empty');
                     return;
                 }
-                moves.push({ source: item.path, destination });
+                moves.push({ source: item.path, destination, name });
             });
 
             if (skippedEmpty.length) {
@@ -464,7 +775,7 @@
                     if (errorCount) {
                         console.warn('Unsorted apply errors:', data.errors);
                     }
-                    scanUnsorted();
+                    loadCategories().then(() => scanUnsorted());
                 })
                 .catch(() => {
                     btn.disabled = false;
@@ -473,7 +784,558 @@
                 });
         }
 
-        scanUnsorted();
+        function refreshLibraryCache() {
+            const status = document.getElementById('library-refresh-status');
+            status.style.color = 'var(--text-muted)';
+            status.textContent = 'Refreshing…';
+            fetch('/api/library/refresh', { method: 'POST' })
+                .then(r => r.json())
+                .then(data => {
+                    status.style.color = data.success ? 'var(--success)' : 'var(--error)';
+                    status.innerHTML = data.success ? (ICON_SVGS.check + ' Refreshed') : 'Could not refresh';
+                    if (data.success) setTimeout(() => { status.textContent = ''; }, 3000);
+                })
+                .catch(() => {
+                    status.style.color = 'var(--error)';
+                    status.textContent = 'Could not reach the server';
+                });
+        }
+
+        // ---- Bulk rename: find/replace across every course/folder name ----
+        let bulkRenameMatches = [];
+
+        function previewBulkRename() {
+            const pattern = document.getElementById('bulk-rename-find').value;
+            const replacement = document.getElementById('bulk-rename-replace').value;
+            const status = document.getElementById('bulk-rename-status');
+            const preview = document.getElementById('bulk-rename-preview');
+            preview.innerHTML = '';
+            if (!pattern) {
+                status.style.color = 'var(--error)';
+                status.textContent = 'Enter text to find first.';
+                return;
+            }
+            status.style.color = 'var(--text-muted)';
+            status.textContent = 'Searching...';
+            fetch(`/api/bulk-rename/preview?pattern=${encodeURIComponent(pattern)}&replacement=${encodeURIComponent(replacement)}`)
+                .then(r => r.json())
+                .then(data => {
+                    bulkRenameMatches = data.matches || [];
+                    renderBulkRenamePreview();
+                })
+                .catch(() => {
+                    status.style.color = 'var(--error)';
+                    status.textContent = 'Could not reach the server.';
+                });
+        }
+
+        function renderBulkRenamePreview() {
+            const status = document.getElementById('bulk-rename-status');
+            const preview = document.getElementById('bulk-rename-preview');
+            if (bulkRenameMatches.length === 0) {
+                status.style.color = 'var(--text-muted)';
+                status.textContent = 'No matches.';
+                preview.innerHTML = '';
+                return;
+            }
+            status.textContent = '';
+            const rows = bulkRenameMatches.map((m, i) => `
+                <div class="bulk-rename-row">
+                    <div class="bulk-rename-row-names">
+                        <div class="bulk-rename-old">${m.old_name}</div>
+                        <div class="bulk-rename-new">→ ${m.new_name}</div>
+                    </div>
+                    <button class="btn btn-secondary btn-sm" onclick="removeBulkRenameMatch(${i})">Remove</button>
+                </div>
+            `).join('');
+            const count = bulkRenameMatches.length;
+            preview.innerHTML = rows +
+                `<button class="btn" style="margin-top: 10px;" onclick="applyBulkRename()">Apply ${count} Rename${count === 1 ? '' : 's'}</button>`;
+        }
+
+        function removeBulkRenameMatch(index) {
+            bulkRenameMatches.splice(index, 1);
+            renderBulkRenamePreview();
+        }
+
+        function applyBulkRename() {
+            if (!confirm(`Rename ${bulkRenameMatches.length} item(s)? This changes real folders on disk.`)) return;
+            const status = document.getElementById('bulk-rename-status');
+            status.style.color = 'var(--text-muted)';
+            status.textContent = 'Applying...';
+            fetch('/api/bulk-rename/apply', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ items: bulkRenameMatches })
+            })
+            .then(r => r.json())
+            .then(data => {
+                const results = data.results || [];
+                const succeeded = results.filter(r => r.success).length;
+                const failed = results.filter(r => !r.success);
+                const activeCourseReset = results.some(r => r.active_course_reset);
+
+                status.style.color = failed.length ? 'var(--error)' : 'var(--success)';
+                let message = `${succeeded} renamed`;
+                if (failed.length) {
+                    message += `, ${failed.length} failed: ` +
+                        failed.map(f => `${f.old_name} (${f.error})`).join('; ');
+                } else {
+                    message += '.';
+                }
+                if (activeCourseReset) {
+                    message += ' Your active course was renamed - reload the main page to pick it up under its new name.';
+                }
+                status.textContent = message;
+
+                bulkRenameMatches = [];
+                document.getElementById('bulk-rename-preview').innerHTML = '';
+                document.getElementById('bulk-rename-find').value = '';
+                document.getElementById('bulk-rename-replace').value = '';
+                loadHiddenList();
+                loadCategories();
+                loadCurateLevel(null, document.getElementById('curate-tree'), true);
+            })
+            .catch(() => {
+                status.style.color = 'var(--error)';
+                status.textContent = 'Could not reach the server.';
+            });
+        }
+
+        // ---- Manage Library: hide/show courses & folders ----
+        function loadHiddenList() {
+            fetch('/api/hidden-paths')
+                .then(r => r.json())
+                .then(data => {
+                    const wrap = document.getElementById('hidden-list-wrap');
+                    const list = document.getElementById('hidden-list');
+                    const items = data.hidden_paths || [];
+                    if (items.length === 0) {
+                        wrap.style.display = 'none';
+                        return;
+                    }
+                    wrap.style.display = 'block';
+                    list.innerHTML = items.map(item => `
+                        <div class="curate-row">
+                            <div class="curate-row-name">
+                                <span>${ICON_SVGS.ban}</span>
+                                <span class="name">${item.name}</span>
+                            </div>
+                            <button class="btn btn-secondary btn-sm" onclick="toggleHidden('${item.path.replace(/'/g, "\\'")}', false)">Show</button>
+                        </div>
+                    `).join('');
+                })
+                .catch(() => {});
+        }
+
+        function loadCurateLevel(path, container, isRoot) {
+            const url = path ? `/library/manage?path=${encodeURIComponent(path)}` : '/library/manage';
+            fetch(url)
+                .then(r => r.json())
+                .then(data => {
+                    if (isRoot) {
+                        document.getElementById('curate-path-bar').textContent = `Browsing ${data.library_path}`;
+                    }
+                    renderCurateLevel(data, container);
+                })
+                .catch(() => {
+                    container.innerHTML = '<p style="color:var(--error);">Could not reach the library scanner.</p>';
+                });
+        }
+
+        function renderCurateLevel(data, container) {
+            if (!data.items || data.items.length === 0) {
+                const reason = (data.errors && data.errors.length) ? data.errors.join(' ') : 'Nothing here.';
+                container.innerHTML = `<div class="curate-empty-hint">${reason}</div>`;
+                return;
+            }
+            container.innerHTML = data.items.map(item => {
+                const safePath = item.path.replace(/'/g, "\\'");
+                const safeName = item.name.replace(/'/g, "\\'");
+                const icon = item.type === 'course' ? ICON_SVGS['graduation-cap'] : ICON_SVGS.folder;
+                const hiddenClass = item.hidden ? 'is-hidden' : '';
+                const moveBtn = `<button class="btn btn-secondary btn-sm" onclick="event.stopPropagation(); startMove(this, '${safePath}', '${safeName}')">Move</button>`;
+                const renameBtn = `<button class="btn btn-secondary btn-sm" onclick="event.stopPropagation(); startRename(this, '${safePath}', '${safeName}')" title="Rename">${ICON_SVGS.pencil}</button>`;
+                const toggleBtn = `<button class="btn btn-secondary btn-sm" onclick="event.stopPropagation(); toggleHidden('${safePath}', ${!item.hidden}, this)">${item.hidden ? 'Show' : 'Hide'}</button>`;
+                const actions = `<div class="curate-actions">${moveBtn}${renameBtn}${toggleBtn}</div>`;
+
+                if (item.type === 'course') {
+                    return `
+                        <div class="curate-row ${hiddenClass}">
+                            <div class="curate-row-name">
+                                <span>${icon}</span>
+                                <span class="name">${item.name}</span>
+                            </div>
+                            ${actions}
+                        </div>
+                    `;
+                }
+                return `
+                    <div class="curate-row ${hiddenClass}" onclick="toggleCurateDir(this, '${safePath}')">
+                        <div class="curate-row-name">
+                            <span class="curate-toggle">▶</span>
+                            <span>${icon}</span>
+                            <span class="name">${item.name}</span>
+                        </div>
+                        ${actions}
+                    </div>
+                    <div class="curate-children" data-loaded="false"></div>
+                `;
+            }).join('');
+        }
+
+        function toggleCurateDir(rowEl, path) {
+            const content = rowEl.nextElementSibling;
+            const toggleIcon = rowEl.querySelector('.curate-toggle');
+            if (!content || !content.classList.contains('curate-children')) return;
+
+            if (content.classList.contains('expanded')) {
+                content.classList.remove('expanded');
+                if (toggleIcon) toggleIcon.textContent = '▶';
+                return;
+            }
+            content.classList.add('expanded');
+            if (toggleIcon) toggleIcon.textContent = '▼';
+
+            if (content.dataset.loaded === 'true') return;
+            content.innerHTML = '<div class="curate-empty-hint">Loading...</div>';
+            content.dataset.loaded = 'true';
+            content.dataset.path = path;
+            loadCurateLevel(path, content, false);
+        }
+
+        function toggleHidden(path, hidden, btnEl) {
+            fetch('/api/hidden-paths', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ path: path, hidden: hidden })
+            })
+            .then(r => r.json())
+            .then(data => {
+                if (data.success) {
+                    loadHiddenList();
+                    // Refresh just the level this toggle happened in, rather
+                    // than collapsing the whole tree back to root.
+                    const container = btnEl ? (btnEl.closest('.curate-children') || document.getElementById('curate-tree'))
+                                             : document.getElementById('curate-tree');
+                    const isRootContainer = container.id === 'curate-tree';
+                    const refreshPath = isRootContainer ? null : container.dataset.path;
+                    loadCurateLevel(refreshPath, container, isRootContainer);
+                }
+            })
+            .catch(() => {});
+        }
+
+        // ---- Manage Library: rename a course/folder in place on disk ----
+        function startRename(btnEl, path, currentName) {
+            const row = btnEl.closest('.curate-row');
+            const nameSpan = row ? row.querySelector('.curate-row-name .name') : null;
+            if (!row || !nameSpan) return;
+
+            let settled = false;
+            const input = document.createElement('input');
+            input.type = 'text';
+            input.className = 'curate-rename-input';
+            input.value = currentName;
+            input.onclick = (e) => e.stopPropagation();
+            nameSpan.replaceWith(input);
+            input.focus();
+            input.select();
+
+            function cancel() {
+                if (settled) return;
+                settled = true;
+                input.replaceWith(nameSpan);
+            }
+            function commit() {
+                if (settled) return;
+                const newName = input.value.trim();
+                if (!newName || newName === currentName) {
+                    cancel();
+                    return;
+                }
+                settled = true;
+                submitRename(btnEl, path, newName, row, nameSpan, input);
+            }
+            input.addEventListener('keydown', (e) => {
+                e.stopPropagation();
+                if (e.key === 'Enter') { e.preventDefault(); commit(); }
+                else if (e.key === 'Escape') { e.preventDefault(); cancel(); }
+            });
+            input.addEventListener('blur', commit);
+        }
+
+        function submitRename(btnEl, path, newName, row, nameSpan, input) {
+            fetch('/api/rename-path', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ path: path, new_name: newName })
+            })
+            .then(r => r.json().then(data => ({ ok: r.ok, data })))
+            .then(({ ok, data }) => {
+                if (!ok || !data.success) {
+                    input.replaceWith(nameSpan); // nameSpan still shows the original, unchanged name
+                    showRowError(row, data.error || 'Rename failed');
+                    return;
+                }
+                if (data.active_course_reset) {
+                    alert('That was your active course - reload the main page to pick it up under its new name.');
+                }
+                loadHiddenList();
+                const container = btnEl.closest('.curate-children') || document.getElementById('curate-tree');
+                const isRootContainer = container.id === 'curate-tree';
+                const refreshPath = isRootContainer ? null : container.dataset.path;
+                loadCurateLevel(refreshPath, container, isRootContainer);
+            })
+            .catch(() => {
+                input.replaceWith(nameSpan);
+                showRowError(row, 'Could not reach the server');
+            });
+        }
+
+        function showRowError(row, message) {
+            let status = row.querySelector('.curate-row-status');
+            if (!status) {
+                status = document.createElement('div');
+                status.className = 'curate-row-status';
+                row.appendChild(status);
+            }
+            status.textContent = message;
+        }
+
+        // ---- Manage Library: move a course/folder elsewhere in the library ----
+        function startMove(btnEl, path, currentName) {
+            const row = btnEl.closest('.curate-row');
+            if (!row) return;
+            const existing = row.nextElementSibling;
+            if (existing && existing.classList.contains('curate-move-panel')) {
+                existing.remove();
+                return;
+            }
+            document.querySelectorAll('.curate-move-panel').forEach(p => p.remove());
+
+            const optionsHtml = categoryOptionsHtml();
+            const panel = document.createElement('div');
+            panel.className = 'curate-move-panel';
+            panel.innerHTML = `
+                <div class="sort-field">
+                    <label>Move "${escapeHtml(currentName)}" to</label>
+                    <div class="dest-picker">
+                        ${ICON_SVGS.folder}
+                        <select class="move-dest-select">
+                            ${optionsHtml}
+                            <option value="${NEW_FOLDER_VALUE}">+ Create new folder…</option>
+                        </select>
+                    </div>
+                    <input type="text" class="move-dest-new-input text-input" style="display: none; margin-top: 6px;" placeholder="e.g. IT/NewCategory">
+                </div>
+                <div class="curate-move-actions">
+                    <button class="btn btn-sm">Move</button>
+                    <button class="btn btn-secondary btn-sm">Cancel</button>
+                </div>
+                <div class="curate-move-status"></div>
+            `;
+            row.after(panel);
+
+            const select = panel.querySelector('.move-dest-select');
+            const newInput = panel.querySelector('.move-dest-new-input');
+            select.addEventListener('change', () => {
+                const showNew = select.value === NEW_FOLDER_VALUE;
+                newInput.style.display = showNew ? 'block' : 'none';
+                if (showNew) newInput.focus();
+            });
+            if (!optionsHtml) {
+                select.value = NEW_FOLDER_VALUE;
+                newInput.style.display = 'block';
+                newInput.focus();
+            }
+
+            const [moveBtn, cancelBtn] = panel.querySelectorAll('.curate-move-actions button');
+            cancelBtn.onclick = () => panel.remove();
+            moveBtn.onclick = () => submitMove(panel, btnEl, path);
+        }
+
+        function submitMove(panel, btnEl, path) {
+            const select = panel.querySelector('.move-dest-select');
+            const newInput = panel.querySelector('.move-dest-new-input');
+            const status = panel.querySelector('.curate-move-status');
+            const usingNew = select.value === NEW_FOLDER_VALUE;
+            const destination = (usingNew ? newInput.value : select.value).trim();
+            if (!destination) {
+                status.style.color = 'var(--error)';
+                status.textContent = 'Choose or type a destination first.';
+                if (usingNew) newInput.focus();
+                return;
+            }
+            status.style.color = 'var(--text-muted)';
+            status.textContent = 'Moving…';
+            fetch('/api/library/move', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ source: path, destination })
+            })
+            .then(r => r.json().then(data => ({ ok: r.ok, data })))
+            .then(({ ok, data }) => {
+                if (!ok || !data.success) {
+                    status.style.color = 'var(--error)';
+                    status.textContent = data.error || 'Move failed';
+                    return;
+                }
+                if (data.active_course_reset) {
+                    alert('That was your active course - reload the main page to pick it up under its new location.');
+                }
+                loadHiddenList();
+                loadCategories();
+                const container = btnEl.closest('.curate-children') || document.getElementById('curate-tree');
+                const isRootContainer = container.id === 'curate-tree';
+                const refreshPath = isRootContainer ? null : container.dataset.path;
+                loadCurateLevel(refreshPath, container, isRootContainer);
+            })
+            .catch(() => {
+                status.style.color = 'var(--error)';
+                status.textContent = 'Could not reach the server.';
+            });
+        }
+
+        // ---- Duplicate Courses ----
+        function scanDuplicates() {
+            const btn = document.getElementById('dup-scan-btn');
+            const status = document.getElementById('dup-status');
+            const results = document.getElementById('dup-results');
+            btn.disabled = true;
+            status.style.color = 'var(--text-muted)';
+            status.textContent = 'Scanning…';
+            results.innerHTML = '';
+            fetch('/api/library/duplicates')
+                .then(r => r.json())
+                .then(data => {
+                    btn.disabled = false;
+                    const groups = data.groups || [];
+                    if (!groups.length) {
+                        status.style.color = 'var(--success)';
+                        status.textContent = `No likely duplicates found across ${data.course_count} course${data.course_count === 1 ? '' : 's'}.`;
+                        return;
+                    }
+                    status.style.color = 'var(--text-muted)';
+                    status.textContent = `${groups.length} possible duplicate group${groups.length === 1 ? '' : 's'}, out of ${data.course_count} courses.`;
+                    results.innerHTML = groups.map(group => `
+                        <div class="dup-group">
+                            <div class="dup-group-header">${Math.round(group.similarity * 100)}% similar</div>
+                            ${group.courses.map(c => `
+                                <div class="dup-course-row">
+                                    <span class="dup-course-name">${escapeHtml(c.name)}</span>
+                                    <span class="dup-course-path">${escapeHtml(c.path)}</span>
+                                    <button class="btn btn-secondary btn-sm" onclick="hideDuplicateCourse(this, '${c.path.replace(/'/g, "\\'")}')">Hide</button>
+                                </div>
+                            `).join('')}
+                        </div>
+                    `).join('');
+                })
+                .catch(() => {
+                    btn.disabled = false;
+                    status.style.color = 'var(--error)';
+                    status.textContent = 'Could not reach the server.';
+                });
+        }
+
+        function hideDuplicateCourse(btnEl, path) {
+            fetch('/api/hidden-paths', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ path: path, hidden: true })
+            })
+            .then(r => r.json())
+            .then(data => {
+                if (data.success) {
+                    btnEl.disabled = true;
+                    btnEl.textContent = 'Hidden';
+                    const row = btnEl.closest('.dup-course-row');
+                    if (row) row.style.opacity = '0.5';
+                }
+            })
+            .catch(() => {});
+        }
+
+        // ---- Stale References ----
+        let lastStaleItems = [];
+
+        function scanStaleReferences() {
+            const btn = document.getElementById('stale-scan-btn');
+            const status = document.getElementById('stale-status');
+            const results = document.getElementById('stale-results');
+            btn.disabled = true;
+            status.style.color = 'var(--text-muted)';
+            status.textContent = 'Scanning…';
+            results.innerHTML = '';
+            fetch('/api/library/stale-references')
+                .then(r => r.json())
+                .then(data => {
+                    btn.disabled = false;
+                    const categoryLabels = { hidden: 'Hidden', next_up: 'Next Up', recent_views: 'Recently Viewed' };
+                    const items = [];
+                    for (const category of ['hidden', 'next_up', 'recent_views']) {
+                        for (const entry of (data[category] || [])) {
+                            items.push({ path: entry.path, name: entry.name, category, label: categoryLabels[category] });
+                        }
+                    }
+                    if (!items.length) {
+                        status.style.color = 'var(--success)';
+                        status.textContent = 'No stale references found.';
+                        return;
+                    }
+                    status.textContent = '';
+                    lastStaleItems = items;
+                    results.innerHTML = `
+                        <div id="stale-rows">${items.map((item, i) => `
+                            <div class="bulk-rename-row" data-idx="${i}">
+                                <div class="bulk-rename-row-names">
+                                    <span class="sort-badge new_folder">${item.label}</span>
+                                    ${escapeHtml(item.name)}
+                                </div>
+                                <button class="btn btn-secondary btn-sm" onclick="removeStaleItem(${i})">Remove</button>
+                            </div>
+                        `).join('')}</div>
+                        <button class="btn" style="margin-top: 10px;" onclick="cleanAllStaleReferences()">Remove All ${items.length}</button>
+                    `;
+                })
+                .catch(() => {
+                    btn.disabled = false;
+                    status.style.color = 'var(--error)';
+                    status.textContent = 'Could not reach the server.';
+                });
+        }
+
+        function removeStaleItem(index) {
+            const item = lastStaleItems[index];
+            if (!item) return;
+            fetch('/api/library/stale-references/clean', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ items: [{ category: item.category, path: item.path }] })
+            })
+            .then(r => r.json())
+            .then(data => {
+                if (data.success) scanStaleReferences();
+            })
+            .catch(() => {});
+        }
+
+        function cleanAllStaleReferences() {
+            if (!lastStaleItems.length) return;
+            if (!confirm(`Remove all ${lastStaleItems.length} stale reference(s)? This does not touch any files on disk.`)) return;
+            fetch('/api/library/stale-references/clean', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ items: lastStaleItems.map(i => ({ category: i.category, path: i.path })) })
+            })
+            .then(r => r.json())
+            .then(() => scanStaleReferences())
+            .catch(() => {});
+        }
+
+        loadCategories().then(() => scanUnsorted());
+        loadHiddenList();
+        loadCurateLevel(null, document.getElementById('curate-tree'), true);
     </script>
 </body>
 </html>