docs: sync CLAUDE.md, AGENTS.md and architecture docs with actual code

Full audit of CLAUDE.md, AGENTS.md, README.md and docs/architecture/
against the codebase; every fix is backed by current code:

- remove documented-but-unimplemented IPTVNATOR_DISABLE_HARDWARE_ACCELERATION
  flag (no reads anywhere in apps/, libs/, tools/)
- CLAUDE.md: add epg_channel_mappings to the schema table list
- m3u-playlist-module: *-tab dirs -> *-view (+recent-view), selectActivePlaylist,
  real PlaylistState shape, ChannelEpgMetadata instead of removed EnrichedChannel,
  actual /workspace/playlists routes, per-view outputs, live-epg-panel-state key
- workspace-dashboard: per-rail Settings.dashboardRails toggles, three missing
  rails in the diagram, split live-favorites/recent-live rails,
  welcome-dashboard empty-state type, RECENTLY_WATCHED_LIVE_TV title key
- stalker-portal: CategoryContentViewComponent for vod/series, collection-route
  components for favorites/recent, corrected series-view/favorites-button paths,
  actor/:personId route, epg panel selectors
- category-management: reloadCategories lives in with-content.feature.ts,
  workspace-context-panel owns the dialog, XtreamPendingRestoreService flow
- stalker-mock-server (+app README): scenario-seeded faker, resetAll() clears
  content cache too, ordinal season episode ids, handlers/ dir location
- sqlite-db-worker: cancellation shipped (drop from out-of-scope), full
  operations module list
- portal-detail-navigation: replace three removed component paths
- tmdb-metadata-enrichment: details cache keys are id:<tmdbId>|v2
- electron-security: CSP frame-src youtube-nocookie exception,
  sandbox: !frameCopyExperiment nuance
- download-manager: libs/portal/xtream instead of xtream-electron folder,
  data-driven downloads nav, drop removed app-search-result-item note
- playlist-backup-restore: settings-backup facade owns the import handoff
- workspace-shell: functional workspaceEntryRedirect, playlists route children
- iptvnator-ui-guidelines: EPG card radius 11px, detail-view mixin is `base`
- embedded-mpv-native, player-controls-contract: minor precision fixes

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

README.md

@@ -300,13 +300,6 @@ This redirects the SQLite database, Electron user data, and local config under
 the given directory. Delete that directory whenever you want a fresh empty
 state.
 
-If you need to debug renderer freezes or GPU/compositor issues in Electron, you
-can disable hardware acceleration for a run:
-
-```
-$ IPTVNATOR_DISABLE_HARDWARE_ACCELERATION=1 pnpm run serve:backend
-```
-
 If you need startup diagnostics for a white screen or a frozen route, you can
 also turn on opt-in Electron tracing. These logs are written to the Electron
 terminal output so they still help when the renderer DevTools never open: