diff --git a/src/app/api/movies/route.ts b/src/app/api/movies/route.ts
index 12ba6e9..cbb2ee6 100644
--- a/src/app/api/movies/route.ts
+++ b/src/app/api/movies/route.ts
@@ -64,7 +64,7 @@ export async function DELETE(request: NextRequest) {
     return NextResponse.json({ error: 'Failed to delete movie directory' }, { status: 500 })
   }
 
-  removeAllAssignmentsForItem(`${libraryId}:${movieId}`)
+  removeAllAssignmentsForItem(`${libraryId}:movie:${movieId}`)
 
   return new NextResponse(null, { status: 204 })
 }
diff --git a/src/app/api/tags/assignments/route.ts b/src/app/api/tags/assignments/route.ts
index 887ddd7..1b6ddb5 100644
--- a/src/app/api/tags/assignments/route.ts
+++ b/src/app/api/tags/assignments/route.ts
@@ -2,27 +2,27 @@ import { NextRequest, NextResponse } from 'next/server'
 import { getResolvedTagsForItem, addTagToItem, removeTagFromItem } from '@/lib/tags'
 import { requireLibraryAccess } from '@/lib/auth'
 
-function extractLibraryId(mediaKey: string): string | null {
-  const colonIdx = mediaKey.indexOf(':')
+function extractLibraryId(itemKey: string): string | null {
+  const colonIdx = itemKey.indexOf(':')
   if (colonIdx === -1) return null
-  return mediaKey.slice(0, colonIdx)
+  return itemKey.slice(0, colonIdx)
 }
 
 export async function GET(request: NextRequest) {
   try {
     const { searchParams } = new URL(request.url)
-    const mediaKey = searchParams.get('mediaKey')
-    if (!mediaKey) {
-      return NextResponse.json({ error: 'mediaKey is required' }, { status: 400 })
+    const itemKey = searchParams.get('itemKey')
+    if (!itemKey) {
+      return NextResponse.json({ error: 'itemKey is required' }, { status: 400 })
     }
-    const libraryId = extractLibraryId(mediaKey)
+    const libraryId = extractLibraryId(itemKey)
     if (!libraryId) {
-      return NextResponse.json({ error: 'Invalid mediaKey' }, { status: 400 })
+      return NextResponse.json({ error: 'Invalid itemKey' }, { status: 400 })
     }
     const auth = await requireLibraryAccess(request, libraryId)
     if (auth instanceof NextResponse) return auth
 
-    return NextResponse.json(getResolvedTagsForItem(mediaKey))
+    return NextResponse.json(getResolvedTagsForItem(itemKey))
   } catch (err) {
     return NextResponse.json({ error: (err as Error).message }, { status: 500 })
   }
@@ -30,18 +30,18 @@ export async function GET(request: NextRequest) {
 
 export async function POST(request: NextRequest) {
   try {
-    const { mediaKey, tagId } = await request.json()
-    if (!mediaKey || !tagId) {
-      return NextResponse.json({ error: 'mediaKey and tagId are required' }, { status: 400 })
+    const { itemKey, tagId } = await request.json()
+    if (!itemKey || !tagId) {
+      return NextResponse.json({ error: 'itemKey and tagId are required' }, { status: 400 })
     }
-    const libraryId = extractLibraryId(mediaKey)
+    const libraryId = extractLibraryId(itemKey)
     if (!libraryId) {
-      return NextResponse.json({ error: 'Invalid mediaKey' }, { status: 400 })
+      return NextResponse.json({ error: 'Invalid itemKey' }, { status: 400 })
     }
     const auth = await requireLibraryAccess(request, libraryId)
     if (auth instanceof NextResponse) return auth
 
-    addTagToItem(mediaKey, tagId)
+    addTagToItem(itemKey, tagId)
     return new NextResponse(null, { status: 204 })
   } catch (err) {
     return NextResponse.json({ error: (err as Error).message }, { status: 400 })
@@ -51,19 +51,19 @@ export async function POST(request: NextRequest) {
 export async function DELETE(request: NextRequest) {
   try {
     const { searchParams } = new URL(request.url)
-    const mediaKey = searchParams.get('mediaKey')
+    const itemKey = searchParams.get('itemKey')
     const tagId = searchParams.get('tagId')
-    if (!mediaKey || !tagId) {
-      return NextResponse.json({ error: 'mediaKey and tagId are required' }, { status: 400 })
+    if (!itemKey || !tagId) {
+      return NextResponse.json({ error: 'itemKey and tagId are required' }, { status: 400 })
     }
-    const libraryId = extractLibraryId(mediaKey)
+    const libraryId = extractLibraryId(itemKey)
     if (!libraryId) {
-      return NextResponse.json({ error: 'Invalid mediaKey' }, { status: 400 })
+      return NextResponse.json({ error: 'Invalid itemKey' }, { status: 400 })
     }
     const auth = await requireLibraryAccess(request, libraryId)
     if (auth instanceof NextResponse) return auth
 
-    removeTagFromItem(mediaKey, tagId)
+    removeTagFromItem(itemKey, tagId)
     return new NextResponse(null, { status: 204 })
   } catch (err) {
     return NextResponse.json({ error: (err as Error).message }, { status: 400 })
diff --git a/src/app/api/tv/route.ts b/src/app/api/tv/route.ts
index a297ce9..b063d0b 100644
--- a/src/app/api/tv/route.ts
+++ b/src/app/api/tv/route.ts
@@ -74,7 +74,7 @@ export async function DELETE(request: NextRequest) {
     return NextResponse.json({ error: 'Failed to delete series directory' }, { status: 500 })
   }
 
-  removeAllAssignmentsForItem(`${libraryId}:${seriesId}`)
+  removeAllAssignmentsForItem(`${libraryId}:tv_series:${seriesId}`)
 
   return new NextResponse(null, { status: 204 })
 }
diff --git a/src/components/DoomScrollView.tsx b/src/components/DoomScrollView.tsx
index e9c4c38..4de737d 100644
--- a/src/components/DoomScrollView.tsx
+++ b/src/components/DoomScrollView.tsx
@@ -7,7 +7,7 @@ export interface DoomScrollItem {
   url: string
   name: string
   mediaType: 'video' | 'image'
-  mediaKey?: string
+  itemKey?: string
 }
 
 interface Props {
@@ -16,6 +16,8 @@ interface Props {
   onClose: () => void
 }
 
+const HISTORY_CAP = 100
+
 function pickRandom(items: DoomScrollItem[], excludeRecent: DoomScrollItem[]): DoomScrollItem {
   const excludeCount = Math.min(excludeRecent.length, items.length - 1)
   const recentUrls = new Set(excludeRecent.slice(-excludeCount).map((i) => i.url))
@@ -55,9 +57,9 @@ export default function DoomScrollView({ items, videoContext = 'mixed', onClose
       const next = pickRandom(items, history)
       setHistory((h) => {
         const updated = [...h, next]
-        return updated.length > 100 ? updated.slice(-100) : updated
+        return updated.length > HISTORY_CAP ? updated.slice(-HISTORY_CAP) : updated
       })
-      return idx + 1
+      return Math.min(idx + 1, HISTORY_CAP - 1)
     })
   }, [items, history])
 
diff --git a/src/components/games/GameDetailModal.tsx b/src/components/games/GameDetailModal.tsx
index 30709ef..8d41fcb 100644
--- a/src/components/games/GameDetailModal.tsx
+++ b/src/components/games/GameDetailModal.tsx
@@ -142,7 +142,7 @@ export default function GameDetailModal({ game, libraryId, onClose, onTagsChange
                 <p className="text-xs font-semibold uppercase tracking-wider mb-2" style={{ color: 'var(--text-secondary)' }}>
                   Tags
                 </p>
-                <TagSelector mediaKey={`${libraryId}:${game.id}`} onTagsChanged={onTagsChanged} />
+                <TagSelector itemKey={game.item_key!} onTagsChanged={onTagsChanged} />
               </div>
             </div>
           </>
diff --git a/src/components/games/GamesView.tsx b/src/components/games/GamesView.tsx
index 9379235..a3150a2 100644
--- a/src/components/games/GamesView.tsx
+++ b/src/components/games/GamesView.tsx
@@ -81,7 +81,7 @@ export default function GamesView({ libraryId }: Props) {
       if (!searchMatch) return false
       if (selectedTagIds.size > 0) {
         return item.games.some((g) => {
-          const gameTags = assignments[`${libraryId}:${g.id}`] ?? []
+          const gameTags = assignments[g.item_key!] ?? []
           return [...selectedTagIds].every((id) => gameTags.includes(id))
         })
       }
@@ -89,7 +89,7 @@ export default function GamesView({ libraryId }: Props) {
     }
     if (search && !item.title.toLowerCase().includes(search.toLowerCase())) return false
     if (selectedTagIds.size > 0) {
-      const gameTags = assignments[`${libraryId}:${item.id}`] ?? []
+      const gameTags = assignments[item.item_key!] ?? []
       if (![...selectedTagIds].every((id) => gameTags.includes(id))) return false
     }
     return true
diff --git a/src/components/mixed/ImageLightbox.tsx b/src/components/mixed/ImageLightbox.tsx
index cf27d0a..ebbc7f6 100644
--- a/src/components/mixed/ImageLightbox.tsx
+++ b/src/components/mixed/ImageLightbox.tsx
@@ -9,14 +9,14 @@ interface Props {
   onClose: () => void
   onPrev?: () => void
   onNext?: () => void
-  mediaKey?: string
+  itemKey?: string
   onTagsChanged?: () => void
 }
 
-export default function ImageLightbox({ url, name, onClose, onPrev, onNext, mediaKey, onTagsChanged }: Props) {
+export default function ImageLightbox({ url, name, onClose, onPrev, onNext, itemKey, onTagsChanged }: Props) {
   const overlayRef = useRef<HTMLDivElement>(null)
   const [showTags, setShowTags] = useState(
-    () => !!mediaKey && typeof window !== 'undefined' && window.innerWidth >= 1280
+    () => !!itemKey && typeof window !== 'undefined' && window.innerWidth >= 1280
   )
 
   useEffect(() => {
@@ -50,7 +50,7 @@ export default function ImageLightbox({ url, name, onClose, onPrev, onNext, medi
           {name}
         </span>
         <div className="flex items-center gap-2 flex-shrink-0">
-          {mediaKey && (
+          {itemKey && (
             <button
               onClick={(e) => { e.stopPropagation(); setShowTags((v) => !v) }}
               className="w-12 h-12 rounded-full flex items-center justify-center text-sm transition-colors"
@@ -125,7 +125,7 @@ export default function ImageLightbox({ url, name, onClose, onPrev, onNext, medi
             <p className="text-xs font-semibold uppercase tracking-wider mb-3" style={{ color: 'var(--text-secondary)' }}>
               Tags
             </p>
-            <TagSelector mediaKey={mediaKey!} onTagsChanged={onTagsChanged} />
+            <TagSelector itemKey={itemKey!} onTagsChanged={onTagsChanged} />
           </div>
         </div>
       ) : (
diff --git a/src/components/mixed/MixedView.tsx b/src/components/mixed/MixedView.tsx
index 3d92a37..7f6e9b6 100644
--- a/src/components/mixed/MixedView.tsx
+++ b/src/components/mixed/MixedView.tsx
@@ -7,6 +7,7 @@ import ImageLightbox from './ImageLightbox'
 import TagSelector from '@/components/tags/TagSelector'
 import FilterPanel from '@/components/FilterPanel'
 import DoomScrollView, { type DoomScrollItem } from '@/components/DoomScrollView'
+import { isBrowserPlayable } from '@/lib/browser-media'
 
 interface Props {
   libraryId: string
@@ -14,11 +15,11 @@ interface Props {
 }
 
 type ModalState =
-  | { type: 'video'; url: string; name: string; mediaKey: string; mediaIndex: number }
-  | { type: 'image'; url: string; name: string; mediaKey: string; mediaIndex: number }
+  | { type: 'video'; url: string; name: string; itemKey: string; mediaIndex: number }
+  | { type: 'image'; url: string; name: string; itemKey: string; mediaIndex: number }
   | null
 
-type TagPanelState = { entry: FileEntry; mediaKey: string } | null
+type TagPanelState = { entry: FileEntry; itemKey: string } | null
 
 export default function MixedView({ libraryId, initialPath }: Props) {
   const [currentPath, setCurrentPath] = useState(initialPath)
@@ -100,11 +101,11 @@ export default function MixedView({ libraryId, initialPath }: Props) {
     fetchRecursive()
   }, [filtersActive, fetchRecursive])
 
-  const mediaKeyFor = (entry: FileEntry) => {
+  const itemKeyFor = (entry: FileEntry) => {
     // In recursive mode entry.name is already the full relative path from the library root
-    if (filtersActive) return `${libraryId}:${encodeURIComponent(entry.name)}`
+    if (filtersActive) return `${libraryId}:mixed_file:${encodeURIComponent(entry.name)}`
     const rel = currentPath ? `${currentPath}/${entry.name}` : entry.name
-    return `${libraryId}:${encodeURIComponent(rel)}`
+    return `${libraryId}:mixed_file:${encodeURIComponent(rel)}`
   }
 
   const sourceEntries = filtersActive ? recursiveEntries : (listing?.entries ?? [])
@@ -112,7 +113,7 @@ export default function MixedView({ libraryId, initialPath }: Props) {
   const filteredEntries = sourceEntries.filter((entry) => {
     if (search && !entry.name.toLowerCase().includes(search.toLowerCase())) return false
     if (selectedTagIds.size > 0 && entry.type !== 'directory') {
-      const entryTags = assignments[mediaKeyFor(entry)] ?? []
+      const entryTags = assignments[itemKeyFor(entry)] ?? []
       if (![...selectedTagIds].every((id) => entryTags.includes(id))) return false
     }
     return true
@@ -124,11 +125,11 @@ export default function MixedView({ libraryId, initialPath }: Props) {
 
   const openMediaEntry = (entry: FileEntry, idx: number) => {
     if (!entry.url) return
-    const mediaKey = mediaKeyFor(entry)
+    const itemKey = itemKeyFor(entry)
     if (entry.mediaType === 'video') {
-      setModal({ type: 'video', url: entry.url, name: entry.name, mediaKey, mediaIndex: idx })
+      setModal({ type: 'video', url: entry.url, name: entry.name, itemKey, mediaIndex: idx })
     } else if (entry.mediaType === 'image') {
-      setModal({ type: 'image', url: entry.url, name: entry.name, mediaKey, mediaIndex: idx })
+      setModal({ type: 'image', url: entry.url, name: entry.name, itemKey, mediaIndex: idx })
     }
   }
 
@@ -155,7 +156,7 @@ export default function MixedView({ libraryId, initialPath }: Props) {
   }
 
   const handleTagEntry = (entry: FileEntry) => {
-    setTagPanel({ entry, mediaKey: mediaKeyFor(entry) })
+    setTagPanel({ entry, itemKey: itemKeyFor(entry) })
   }
 
   const navigateUp = () => {
@@ -200,7 +201,7 @@ export default function MixedView({ libraryId, initialPath }: Props) {
   // When filters are active, doom scroll uses filteredEntries (already filtered by search/tags).
   // When no filters, doom scroll uses the full recursiveEntries.
   const doomScrollItems: DoomScrollItem[] = (filtersActive ? filteredEntries : recursiveEntries)
-    .filter((e) => e.type === 'file' && (e.mediaType === 'video' || e.mediaType === 'image') && e.url)
+    .filter((e) => e.type === 'file' && (e.mediaType === 'video' || e.mediaType === 'image') && e.url && isBrowserPlayable(e.name))
     .map((e) => ({ url: e.url!, name: e.name, mediaType: e.mediaType as 'video' | 'image' }))
 
   return (
@@ -326,7 +327,7 @@ export default function MixedView({ libraryId, initialPath }: Props) {
         <VideoPlayerModal
           url={modal.url}
           name={modal.name}
-          mediaKey={modal.mediaKey}
+          itemKey={modal.itemKey}
           onTagsChanged={() => { setFilterRefreshKey((k) => k + 1); fetchAssignments() }}
           onClose={() => setModal(null)}
           onPrev={modal.mediaIndex > 0 ? () => navigateModal(-1) : undefined}
@@ -337,7 +338,7 @@ export default function MixedView({ libraryId, initialPath }: Props) {
         <ImageLightbox
           url={modal.url}
           name={modal.name}
-          mediaKey={modal.mediaKey}
+          itemKey={modal.itemKey}
           onTagsChanged={() => { setFilterRefreshKey((k) => k + 1); fetchAssignments() }}
           onClose={() => setModal(null)}
           onPrev={modal.mediaIndex > 0 ? () => navigateModal(-1) : undefined}
@@ -378,7 +379,7 @@ export default function MixedView({ libraryId, initialPath }: Props) {
             </div>
             <div className="px-5 py-4">
               <TagSelector
-                mediaKey={tagPanel.mediaKey}
+                itemKey={tagPanel.itemKey}
                 onTagsChanged={() => { setFilterRefreshKey((k) => k + 1); fetchAssignments() }}
               />
             </div>
diff --git a/src/components/mixed/VideoPlayerModal.tsx b/src/components/mixed/VideoPlayerModal.tsx
index eb36aa0..495aa5a 100644
--- a/src/components/mixed/VideoPlayerModal.tsx
+++ b/src/components/mixed/VideoPlayerModal.tsx
@@ -10,19 +10,19 @@ interface Props {
   onClose: () => void
   onPrev?: () => void
   onNext?: () => void
-  mediaKey?: string
+  itemKey?: string
   onTagsChanged?: () => void
   context?: 'mixed' | 'movies' | 'tv'
 }
 
-export default function VideoPlayerModal({ url, name, onClose, onPrev, onNext, mediaKey, onTagsChanged, context = 'mixed' }: Props) {
+export default function VideoPlayerModal({ url, name, onClose, onPrev, onNext, itemKey, onTagsChanged, context = 'mixed' }: Props) {
   const settings = useUserSettings()
   const autoPlay = context === 'mixed' ? settings.mixedAutoplay : context === 'movies' ? settings.moviesAutoplay : settings.tvAutoplay
   const loop     = context === 'mixed' ? settings.mixedLoop     : context === 'movies' ? settings.moviesLoop     : settings.tvLoop
   const muted    = context === 'mixed' ? settings.mixedMuted    : context === 'movies' ? settings.moviesMuted    : settings.tvMuted
   const overlayRef = useRef<HTMLDivElement>(null)
   const [showTags, setShowTags] = useState(
-    () => !!mediaKey && typeof window !== 'undefined' && window.innerWidth >= 1280
+    () => !!itemKey && typeof window !== 'undefined' && window.innerWidth >= 1280
   )
 
   useEffect(() => {
@@ -56,7 +56,7 @@ export default function VideoPlayerModal({ url, name, onClose, onPrev, onNext, m
           {name}
         </span>
         <div className="flex items-center gap-2 flex-shrink-0">
-          {mediaKey && (
+          {itemKey && (
             <button
               onClick={(e) => { e.stopPropagation(); setShowTags((v) => !v) }}
               className="w-8 h-8 rounded-full flex items-center justify-center text-sm transition-colors"
@@ -134,7 +134,7 @@ export default function VideoPlayerModal({ url, name, onClose, onPrev, onNext, m
             <p className="text-xs font-semibold uppercase tracking-wider mb-3" style={{ color: 'var(--text-secondary)' }}>
               Tags
             </p>
-            <TagSelector mediaKey={mediaKey!} onTagsChanged={onTagsChanged} />
+            <TagSelector itemKey={itemKey!} onTagsChanged={onTagsChanged} />
           </div>
         </div>
       ) : (
diff --git a/src/components/movies/MovieDetailModal.tsx b/src/components/movies/MovieDetailModal.tsx
index 2abe176..7baa477 100644
--- a/src/components/movies/MovieDetailModal.tsx
+++ b/src/components/movies/MovieDetailModal.tsx
@@ -85,7 +85,7 @@ export default function MovieDetailModal({ movie, libraryId, onClose, onPrev, on
       <VideoPlayerModal
         url={videoUrl}
         name={movie.title}
-        mediaKey={`${libraryId}:${movie.id}`}
+        itemKey={movie.item_key!}
         onTagsChanged={onTagsChanged}
         onClose={() => setPlaying(false)}
         onPrev={onPrev}
@@ -288,7 +288,7 @@ export default function MovieDetailModal({ movie, libraryId, onClose, onPrev, on
             <p className="text-xs font-semibold uppercase tracking-wider mb-2" style={{ color: 'var(--text-secondary)' }}>
               Tags
             </p>
-            <TagSelector mediaKey={`${libraryId}:${movie.id}`} onTagsChanged={onTagsChanged} />
+            <TagSelector itemKey={movie.item_key!} onTagsChanged={onTagsChanged} />
           </div>
         </div>
       </div>
diff --git a/src/components/movies/MoviesView.tsx b/src/components/movies/MoviesView.tsx
index f4ac72b..cc446d1 100644
--- a/src/components/movies/MoviesView.tsx
+++ b/src/components/movies/MoviesView.tsx
@@ -5,6 +5,7 @@ import type { Movie } from '@/types'
 import MovieDetailModal from './MovieDetailModal'
 import FilterPanel from '@/components/FilterPanel'
 import DoomScrollView, { type DoomScrollItem } from '@/components/DoomScrollView'
+import { isBrowserPlayable } from '@/lib/browser-media'
 
 interface Props {
   libraryId: string
@@ -57,7 +58,7 @@ export default function MoviesView({ libraryId }: Props) {
   const filtered = movies.filter((movie) => {
     if (search && !movie.title.toLowerCase().includes(search.toLowerCase())) return false
     if (selectedTagIds.size > 0) {
-      const movieTags = assignments[`${libraryId}:${movie.id}`] ?? []
+      const movieTags = assignments[movie.item_key!] ?? []
       if (![...selectedTagIds].every((id) => movieTags.includes(id))) return false
     }
     return true
@@ -74,7 +75,7 @@ export default function MoviesView({ libraryId }: Props) {
 
   const handleDoomScroll = () => {
     // Use filtered movies — respects any active search/tag filters automatically
-    const items: DoomScrollItem[] = filtered.map((m) => ({
+    const items: DoomScrollItem[] = filtered.filter((m) => isBrowserPlayable(m.videoPath)).map((m) => ({
       url: `/api/file?libraryId=${encodeURIComponent(libraryId)}&path=${encodeURIComponent(m.videoPath)}`,
       name: m.title,
       mediaType: 'video' as const,
diff --git a/src/components/tags/TagSelector.tsx b/src/components/tags/TagSelector.tsx
index 4f03cc9..527b4e4 100644
--- a/src/components/tags/TagSelector.tsx
+++ b/src/components/tags/TagSelector.tsx
@@ -5,7 +5,7 @@ import type { Tag, TagCategory } from '@/types'
 import TagBadge from './TagBadge'
 
 interface Props {
-  mediaKey: string
+  itemKey: string
   onTagsChanged?: () => void
 }
 
@@ -14,7 +14,7 @@ interface AllTags {
   tags: Tag[]
 }
 
-export default function TagSelector({ mediaKey, onTagsChanged }: Props) {
+export default function TagSelector({ itemKey, onTagsChanged }: Props) {
   const [assigned, setAssigned] = useState<{ tags: Tag[]; categories: TagCategory[] }>({
     tags: [],
     categories: [],
@@ -39,10 +39,10 @@ export default function TagSelector({ mediaKey, onTagsChanged }: Props) {
   const [savingCategory, setSavingCategory] = useState(false)
 
   const fetchAssigned = useCallback(() => {
-    return fetch(`/api/tags/assignments?mediaKey=${encodeURIComponent(mediaKey)}`)
+    return fetch(`/api/tags/assignments?itemKey=${encodeURIComponent(itemKey)}`)
       .then((r) => r.json())
       .then((data) => setAssigned(data))
-  }, [mediaKey])
+  }, [itemKey])
 
   const fetchAll = useCallback(() => {
     return Promise.all([
@@ -66,14 +66,14 @@ export default function TagSelector({ mediaKey, onTagsChanged }: Props) {
     try {
       if (isAssigned(tag.id)) {
         await fetch(
-          `/api/tags/assignments?mediaKey=${encodeURIComponent(mediaKey)}&tagId=${encodeURIComponent(tag.id)}`,
+          `/api/tags/assignments?itemKey=${encodeURIComponent(itemKey)}&tagId=${encodeURIComponent(tag.id)}`,
           { method: 'DELETE' }
         )
       } else {
         await fetch('/api/tags/assignments', {
           method: 'POST',
           headers: { 'Content-Type': 'application/json' },
-          body: JSON.stringify({ mediaKey, tagId: tag.id }),
+          body: JSON.stringify({ itemKey, tagId: tag.id }),
         })
       }
       await fetchAssigned()
@@ -106,7 +106,7 @@ export default function TagSelector({ mediaKey, onTagsChanged }: Props) {
         fetch('/api/tags/assignments', {
           method: 'POST',
           headers: { 'Content-Type': 'application/json' },
-          body: JSON.stringify({ mediaKey, tagId: newTag.id }),
+          body: JSON.stringify({ itemKey, tagId: newTag.id }),
         }),
         fetchAll(),
       ])
diff --git a/src/components/tv/TvView.tsx b/src/components/tv/TvView.tsx
index c5fb257..9a95816 100644
--- a/src/components/tv/TvView.tsx
+++ b/src/components/tv/TvView.tsx
@@ -8,6 +8,7 @@ import VideoPlayerModal from '@/components/mixed/VideoPlayerModal'
 import TagSelector from '@/components/tags/TagSelector'
 import EpisodeCard from './EpisodeCard'
 import DoomScrollView, { type DoomScrollItem } from '@/components/DoomScrollView'
+import { isBrowserPlayable } from '@/lib/browser-media'
 
 interface Props {
   libraryId: string
@@ -31,7 +32,7 @@ export default function TvView({ libraryId }: Props) {
   const [seriesEpisodeTags, setSeriesEpisodeTags] = useState<Record<string, string[]>>({})
   const [filterRefreshKey, setFilterRefreshKey] = useState(0)
   const [showFilters, setShowFilters] = useState(true)
-  const [tagPanel, setTagPanel] = useState<{ mediaKey: string; title: string } | null>(null)
+  const [tagPanel, setTagPanel] = useState<{ itemKey: string; title: string } | null>(null)
   const [menuOpen, setMenuOpen] = useState(false)
   const [confirming, setConfirming] = useState(false)
   const [deleting, setDeleting] = useState(false)
@@ -184,7 +185,7 @@ export default function TvView({ libraryId }: Props) {
             return seasonEps.flat()
           })
         )
-        items = episodeLists.flat().map((ep) => ({
+        items = episodeLists.flat().filter((ep) => isBrowserPlayable(ep.videoPath)).map((ep) => ({
           url: `/api/file?libraryId=${encodeURIComponent(libraryId)}&path=${encodeURIComponent(ep.videoPath)}`,
           name: ep.title,
           mediaType: 'video' as const,
@@ -209,7 +210,7 @@ export default function TvView({ libraryId }: Props) {
             return seasonEps.flat()
           })
         )
-        items = episodeLists.flat().map((ep) => ({
+        items = episodeLists.flat().filter((ep) => isBrowserPlayable(ep.videoPath)).map((ep) => ({
           url: `/api/file?libraryId=${encodeURIComponent(libraryId)}&path=${encodeURIComponent(ep.videoPath)}`,
           name: ep.title,
           mediaType: 'video' as const,
@@ -229,7 +230,7 @@ export default function TvView({ libraryId }: Props) {
   const filteredSeries = series.filter((s) => {
     if (search && !s.title.toLowerCase().includes(search.toLowerCase())) return false
     if (selectedTagIds.size > 0) {
-      const seriesTags = assignments[`${libraryId}:${s.id}`] ?? []
+      const seriesTags = assignments[s.item_key!] ?? []
       const episodeTags = seriesEpisodeTags[s.id] ?? []
       const allTags = seriesTags.length === 0 ? episodeTags
         : episodeTags.length === 0 ? seriesTags
@@ -242,7 +243,7 @@ export default function TvView({ libraryId }: Props) {
   const filteredEpisodes = episodes.filter((ep) => {
     if (search && !ep.title.toLowerCase().includes(search.toLowerCase())) return false
     if (selectedTagIds.size > 0) {
-      const epTags = assignments[`${libraryId}:${ep.id}`] ?? []
+      const epTags = assignments[ep.item_key!] ?? []
       if (![...selectedTagIds].every((id) => epTags.includes(id))) return false
     }
     return true
@@ -256,7 +257,7 @@ export default function TvView({ libraryId }: Props) {
       <VideoPlayerModal
         url={videoUrl}
         name={playingEpisode.title}
-        mediaKey={`${libraryId}:${playingEpisode.id}`}
+        itemKey={playingEpisode.item_key!}
         onTagsChanged={() => { setFilterRefreshKey((k) => k + 1); fetchAssignments(); fetchSeriesEpisodeTags() }}
         onClose={() => setPlayingEpisodeIndex(null)}
         onPrev={playingEpisodeIndex > 0 ? () => setPlayingEpisodeIndex((i) => (i !== null ? i - 1 : null)) : undefined}
@@ -391,7 +392,7 @@ export default function TvView({ libraryId }: Props) {
                         <div className="absolute inset-0 flex items-center justify-center text-4xl">📺</div>
                       )}
                       <button
-                        onClick={(e) => { e.stopPropagation(); setTagPanel({ mediaKey: `${libraryId}:${s.id}`, title: s.title }) }}
+                        onClick={(e) => { e.stopPropagation(); setTagPanel({ itemKey: s.item_key!, title: s.title }) }}
                         className="absolute top-2 left-2 w-6 h-6 rounded-full items-center justify-center text-xs opacity-0 group-hover:opacity-100 transition-opacity hidden group-hover:flex"
                         style={{ backgroundColor: 'rgba(0,0,0,0.55)', color: '#fff' }}
                         aria-label={`Tag ${s.title}`}
@@ -579,7 +580,7 @@ export default function TvView({ libraryId }: Props) {
                   key={ep.id}
                   episode={ep}
                   onClick={() => setPlayingEpisodeIndex(episodes.indexOf(ep))}
-                  onTag={() => setTagPanel({ mediaKey: `${libraryId}:${ep.id}`, title: ep.title })}
+                  onTag={() => setTagPanel({ itemKey: ep.item_key!, title: ep.title })}
                 />
               ))}
             </div>
@@ -618,7 +619,7 @@ export default function TvView({ libraryId }: Props) {
             </div>
             <div className="px-5 py-4">
               <TagSelector
-                mediaKey={tagPanel.mediaKey}
+                itemKey={tagPanel.itemKey}
                 onTagsChanged={() => { setFilterRefreshKey((k) => k + 1); fetchAssignments(); fetchSeriesEpisodeTags() }}
               />
             </div>
diff --git a/src/lib/browser-media.ts b/src/lib/browser-media.ts
new file mode 100644
index 0000000..99d87cb
--- /dev/null
+++ b/src/lib/browser-media.ts
@@ -0,0 +1,19 @@
+/**
+ * Browser-native media formats safe for use in <video> and <img> elements.
+ * Kept separate from the broader scanner extension sets (media-utils.ts, files.ts)
+ * which include server-side-only formats like .mkv, .avi, .tiff, etc.
+ */
+
+export const BROWSER_VIDEO_EXTENSIONS = new Set(['.mp4', '.webm', '.mov', '.m4v'])
+export const BROWSER_IMAGE_EXTENSIONS = new Set(['.jpg', '.jpeg', '.png', '.gif', '.webp', '.bmp'])
+
+/**
+ * Returns true if the file at `filename` (or path) has a browser-playable extension.
+ * Uses lastIndexOf to avoid importing the Node `path` module in client components.
+ */
+export function isBrowserPlayable(filename: string): boolean {
+  const dot = filename.lastIndexOf('.')
+  if (dot === -1) return false
+  const ext = filename.slice(dot).toLowerCase()
+  return BROWSER_VIDEO_EXTENSIONS.has(ext) || BROWSER_IMAGE_EXTENSIONS.has(ext)
+}
diff --git a/src/lib/db.ts b/src/lib/db.ts
index 54fd02b..d1107f4 100644
--- a/src/lib/db.ts
+++ b/src/lib/db.ts
@@ -32,9 +32,9 @@ function initDb(db: Database.Database): void {
     CREATE UNIQUE INDEX IF NOT EXISTS tags_name_category ON tags(name, category_id);
 
     CREATE TABLE IF NOT EXISTS media_tags (
-      media_key TEXT NOT NULL,
-      tag_id    TEXT NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
-      PRIMARY KEY (media_key, tag_id)
+      item_key TEXT NOT NULL,
+      tag_id   TEXT NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
+      PRIMARY KEY (item_key, tag_id)
     );
 
     CREATE TABLE IF NOT EXISTS libraries (
@@ -101,6 +101,7 @@ function initDb(db: Database.Database): void {
   migrateLibrariesType(db)
   migrateMediaItemsSchema(db)
   migrateMediaItemsFingerprint(db)
+  migrateMediaTagsToItemKey(db)
   seedAppSettings(db)
 }
 
@@ -177,6 +178,56 @@ function migrateMediaItemsFingerprint(db: Database.Database): void {
   }
 }
 
+function migrateMediaTagsToItemKey(db: Database.Database): void {
+  const row = db
+    .prepare("SELECT sql FROM sqlite_master WHERE type='table' AND name='media_tags'")
+    .get() as { sql: string } | undefined
+  if (!row || !row.sql.includes('media_key')) return // Already migrated or table doesn't exist
+
+  // Create replacement table with item_key column
+  db.exec(`
+    CREATE TABLE media_tags_new (
+      item_key TEXT NOT NULL,
+      tag_id   TEXT NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
+      PRIMARY KEY (item_key, tag_id)
+    )
+  `)
+
+  // Build reverse mapping: short media_key → full item_key
+  // Uses same logic as the old itemKeyToMediaKey: libraryId + lastSegment
+  const items = db
+    .prepare('SELECT item_key FROM media_items')
+    .all() as { item_key: string }[]
+
+  const shortToFull: Record<string, string[]> = {}
+  for (const { item_key } of items) {
+    const firstColon = item_key.indexOf(':')
+    const lastColon = item_key.lastIndexOf(':')
+    const libraryId = item_key.slice(0, firstColon)
+    const shortId = item_key.slice(lastColon + 1)
+    const mediaKey = `${libraryId}:${shortId}`
+    ;(shortToFull[mediaKey] ??= []).push(item_key)
+  }
+
+  const tagRows = db
+    .prepare('SELECT media_key, tag_id FROM media_tags')
+    .all() as { media_key: string; tag_id: string }[]
+
+  const insert = db.prepare('INSERT OR IGNORE INTO media_tags_new (item_key, tag_id) VALUES (?, ?)')
+  db.transaction(() => {
+    for (const { media_key, tag_id } of tagRows) {
+      const candidates = shortToFull[media_key]
+      if (!candidates || candidates.length !== 1) continue // orphaned or ambiguous collision
+      insert.run(candidates[0], tag_id)
+    }
+  })()
+
+  db.exec(`
+    DROP TABLE media_tags;
+    ALTER TABLE media_tags_new RENAME TO media_tags;
+  `)
+}
+
 function migrateLibrariesType(db: Database.Database): void {
   const row = db
     .prepare("SELECT sql FROM sqlite_master WHERE type='table' AND name='libraries'")
diff --git a/src/lib/games.ts b/src/lib/games.ts
index 67ab7bc..81fea34 100644
--- a/src/lib/games.ts
+++ b/src/lib/games.ts
@@ -149,6 +149,7 @@ export function gamesFromDb(libraryId: string): (Game | GameSeries)[] {
     const idPart = row.item_key.split(':game_series:')[1] ?? row.item_key
     seriesMap.set(row.item_key, {
       id: idPart,
+      item_key: row.item_key,
       title: row.title ?? decodeURIComponent(idPart),
       coverUrl: meta.coverUrl ?? null,
       wideCoverUrl: meta.wideCoverUrl ?? null,
@@ -163,6 +164,7 @@ export function gamesFromDb(libraryId: string): (Game | GameSeries)[] {
     const idPart = row.item_key.split(':game:')[1] ?? row.item_key
     const game: Game = {
       id: idPart,
+      item_key: row.item_key,
       title: row.title ?? decodeURIComponent(idPart),
       coverUrl: meta.coverUrl ?? null,
       wideCoverUrl: meta.wideCoverUrl ?? null,
diff --git a/src/lib/movies.ts b/src/lib/movies.ts
index fa5e0db..3b110e6 100644
--- a/src/lib/movies.ts
+++ b/src/lib/movies.ts
@@ -97,6 +97,7 @@ export function moviesFromDb(libraryId: string): Movie[] {
     const idPart = row.item_key.split(':movie:')[1] ?? row.item_key
     return {
       id: idPart,
+      item_key: row.item_key,
       title: row.title ?? decodeURIComponent(idPart),
       year: row.year ?? null,
       plot: row.plot ?? null,
diff --git a/src/lib/scanner.ts b/src/lib/scanner.ts
index 526d46a..57155f2 100644
--- a/src/lib/scanner.ts
+++ b/src/lib/scanner.ts
@@ -556,22 +556,6 @@ function detectMoves(
  * Tags on deleted items are intentionally left as orphans — harmless and
  * recoverable if the file reappears.
  */
-/**
- * Converts an item_key (used in media_items) to the media_key format used in
- * media_tags. The UI constructs media_keys as `${libraryId}:${shortId}` where
- * shortId is only the terminal path segment — e.g.:
- *   "lib1:movie:Inception%20(2010)"     → "lib1:Inception%20(2010)"
- *   "lib1:tv_episode:Show:S1:ep.mkv"   → "lib1:ep.mkv"
- *   "lib1:mixed_file:dir%2Ffile.mp4"   → "lib1:dir%2Ffile.mp4"
- */
-function itemKeyToMediaKey(itemKey: string): string {
-  const firstColon = itemKey.indexOf(':')
-  const lastColon = itemKey.lastIndexOf(':')
-  const libraryId = itemKey.slice(0, firstColon)
-  const shortId = itemKey.slice(lastColon + 1)
-  return `${libraryId}:${shortId}`
-}
-
 function reconcileAndPrune(
   db: Database.Database,
   libraryId: string,
@@ -583,11 +567,8 @@ function reconcileAndPrune(
   // Apply moves first (outside transaction so console.log is visible as they happen)
   for (const { oldKey, newKey } of moves) {
     renameItem.run(newKey, oldKey)
-    // Convert item_keys to the media_key format actually used in media_tags
-    const oldMediaKey = itemKeyToMediaKey(oldKey)
-    const newMediaKey = itemKeyToMediaKey(newKey)
-    if (oldMediaKey !== newMediaKey) {
-      reKeyMediaItem(oldMediaKey, newMediaKey)
+    if (oldKey !== newKey) {
+      reKeyMediaItem(oldKey, newKey)
     }
     console.log(`[scanner]   fingerprint match: renamed "${oldKey}" → "${newKey}"`)
   }
diff --git a/src/lib/tags.ts b/src/lib/tags.ts
index 9089ab6..ca5e7f0 100644
--- a/src/lib/tags.ts
+++ b/src/lib/tags.ts
@@ -164,20 +164,20 @@ export function deleteTag(id: string): void {
 
 // ─── Assignments ──────────────────────────────────────────────────────────────
 
-export function addTagToItem(mediaKey: string, tagId: string): void {
+export function addTagToItem(itemKey: string, tagId: string): void {
   const db = getDb()
   const tag = db.prepare('SELECT 1 FROM tags WHERE id = ?').get(tagId)
   if (!tag) throw new Error(`Tag not found: ${tagId}`)
   // INSERT OR IGNORE handles duplicate gracefully
-  db.prepare('INSERT OR IGNORE INTO media_tags (media_key, tag_id) VALUES (?, ?)').run(mediaKey, tagId)
+  db.prepare('INSERT OR IGNORE INTO media_tags (item_key, tag_id) VALUES (?, ?)').run(itemKey, tagId)
 }
 
-export function removeTagFromItem(mediaKey: string, tagId: string): void {
+export function removeTagFromItem(itemKey: string, tagId: string): void {
   const db = getDb()
-  db.prepare('DELETE FROM media_tags WHERE media_key = ? AND tag_id = ?').run(mediaKey, tagId)
+  db.prepare('DELETE FROM media_tags WHERE item_key = ? AND tag_id = ?').run(itemKey, tagId)
 }
 
-export function getResolvedTagsForItem(mediaKey: string): { tags: Tag[]; categories: TagCategory[] } {
+export function getResolvedTagsForItem(itemKey: string): { tags: Tag[]; categories: TagCategory[] } {
   const db = getDb()
 
   const tags = db
@@ -185,10 +185,10 @@ export function getResolvedTagsForItem(mediaKey: string): { tags: Tag[]; categor
       `SELECT t.id, t.name, t.category_id as categoryId
        FROM tags t
        JOIN media_tags mt ON mt.tag_id = t.id
-       WHERE mt.media_key = ?
+       WHERE mt.item_key = ?
        ORDER BY t.name`
     )
-    .all(mediaKey) as Tag[]
+    .all(itemKey) as Tag[]
 
   const categoryIds = [...new Set(tags.map((t) => t.categoryId))]
   const categories: TagCategory[] =
@@ -206,11 +206,11 @@ export function getResolvedTagsForItem(mediaKey: string): { tags: Tag[]; categor
 export function getTagAssignmentsForLibrary(libraryId: string): Record<string, string[]> {
   const db = getDb()
   const rows = db
-    .prepare('SELECT media_key, tag_id FROM media_tags WHERE media_key LIKE ?')
-    .all(`${libraryId}:%`) as { media_key: string; tag_id: string }[]
+    .prepare('SELECT item_key, tag_id FROM media_tags WHERE item_key LIKE ?')
+    .all(`${libraryId}:%`) as { item_key: string; tag_id: string }[]
   const result: Record<string, string[]> = {}
   for (const row of rows) {
-    ;(result[row.media_key] ??= []).push(row.tag_id)
+    ;(result[row.item_key] ??= []).push(row.tag_id)
   }
   return result
 }
@@ -220,49 +220,42 @@ export function getTagAssignmentsForLibrary(libraryId: string): Record<string, s
 export function getSeriesEpisodeTagMap(libraryId: string): Record<string, string[]> {
   const db = getDb()
   const prefix = `${libraryId}:tv_episode:`
-  const episodes = db
-    .prepare('SELECT item_key FROM media_items WHERE library_id = ? AND item_type = ?')
-    .all(libraryId, 'tv_episode') as { item_key: string }[]
-  if (episodes.length === 0) return {}
 
-  const tagRows = db
-    .prepare('SELECT media_key, tag_id FROM media_tags WHERE media_key LIKE ?')
-    .all(`${libraryId}:%`) as { media_key: string; tag_id: string }[]
-  const tagsByMediaKey: Record<string, string[]> = {}
-  for (const row of tagRows) {
-    ;(tagsByMediaKey[row.media_key] ??= []).push(row.tag_id)
-  }
+  // Join media_items with media_tags directly on item_key
+  const rows = db
+    .prepare(
+      `SELECT mi.item_key, mt.tag_id
+       FROM media_items mi
+       JOIN media_tags mt ON mt.item_key = mi.item_key
+       WHERE mi.library_id = ? AND mi.item_type = 'tv_episode'`
+    )
+    .all(libraryId) as { item_key: string; tag_id: string }[]
 
   const result: Record<string, string[]> = {}
-  for (const { item_key } of episodes) {
+  for (const { item_key, tag_id } of rows) {
     if (!item_key.startsWith(prefix)) continue
     // item_key: "libraryId:tv_episode:seriesId:seasonId:episodeId"
     const parts = item_key.split(':')
     if (parts.length < 5) continue
     const seriesId = parts[2]
-    const episodeId = parts[parts.length - 1]
-    const episodeTags = tagsByMediaKey[`${libraryId}:${episodeId}`]
-    if (!episodeTags) continue
     const seriesTags = (result[seriesId] ??= [])
-    for (const tagId of episodeTags) {
-      if (!seriesTags.includes(tagId)) seriesTags.push(tagId)
-    }
+    if (!seriesTags.includes(tag_id)) seriesTags.push(tag_id)
   }
   return result
 }
 
 export function removeAllAssignmentsForLibrary(libraryId: string): void {
   const db = getDb()
-  db.prepare("DELETE FROM media_tags WHERE media_key LIKE ?").run(`${libraryId}:%`)
+  db.prepare('DELETE FROM media_tags WHERE item_key LIKE ?').run(`${libraryId}:%`)
 }
 
-export function removeAllAssignmentsForItem(mediaKey: string): void {
+export function removeAllAssignmentsForItem(itemKey: string): void {
   const db = getDb()
-  db.prepare("DELETE FROM media_tags WHERE media_key = ?").run(mediaKey)
+  db.prepare('DELETE FROM media_tags WHERE item_key = ?').run(itemKey)
 }
 
 export function reKeyMediaItem(oldKey: string, newKey: string): void {
   getDb()
-    .prepare('UPDATE media_tags SET media_key = ? WHERE media_key = ?')
+    .prepare('UPDATE media_tags SET item_key = ? WHERE item_key = ?')
     .run(newKey, oldKey)
 }
diff --git a/src/lib/tv.ts b/src/lib/tv.ts
index 8e5c931..c46a395 100644
--- a/src/lib/tv.ts
+++ b/src/lib/tv.ts
@@ -215,6 +215,7 @@ export function tvSeriesFromDb(libraryId: string): TvSeries[] {
     const idPart = row.item_key.split(':tv_series:')[1] ?? row.item_key
     return {
       id: idPart,
+      item_key: row.item_key,
       title: row.title ?? decodeURIComponent(idPart),
       year: row.year ?? null,
       plot: row.plot ?? null,
@@ -242,6 +243,7 @@ export function tvSeasonsFromDb(libraryId: string, seriesId: string): TvSeason[]
       const seasonId = parts[1]?.split(':').slice(1).join(':') ?? row.item_key
       return {
         id: seasonId,
+        item_key: row.item_key,
         seriesId,
         title: row.title ?? seasonId,
         seasonNumber: meta.seasonNumber ?? null,
@@ -276,6 +278,7 @@ export function tvEpisodesFromDb(
       const episodeId = suffix.split(':').slice(2).join(':')
       return {
         id: episodeId,
+        item_key: row.item_key,
         title: row.title ?? decodeURIComponent(episodeId),
         episodeNumber: meta.episodeNumber ?? null,
         seasonNumber: meta.seasonNumber ?? null,
diff --git a/src/types/index.ts b/src/types/index.ts
index 830332a..c292ff0 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -10,6 +10,7 @@ export interface Library {
 
 export interface Game {
   id: string
+  item_key?: string
   title: string
   coverUrl: string | null
   wideCoverUrl: string | null
@@ -18,6 +19,7 @@ export interface Game {
 
 export interface GameSeries {
   id: string
+  item_key?: string
   title: string
   coverUrl: string | null
   wideCoverUrl: string | null
@@ -36,6 +38,7 @@ export interface FileEntry {
 
 export interface Movie {
   id: string
+  item_key?: string
   title: string
   year: number | null
   plot: string | null
@@ -49,6 +52,7 @@ export interface Movie {
 
 export interface TvSeries {
   id: string
+  item_key?: string
   title: string
   year: number | null
   plot: string | null
@@ -61,6 +65,7 @@ export interface TvSeries {
 
 export interface TvSeason {
   id: string
+  item_key?: string
   seriesId: string
   title: string
   seasonNumber: number | null
@@ -70,6 +75,7 @@ export interface TvSeason {
 
 export interface TvEpisode {
   id: string
+  item_key?: string
   title: string
   episodeNumber: number | null
   seasonNumber: number | null