fix(plex,channels): address R13 S2 review findings

- Shared usePlexClearFilters hook replaces the duplicated clearAll (was copied in
  PlexBrowse and PlexSidebar) — one "reset every Plex narrowing" both call.
- The Plex duration chip's minutes unit is localized (plex.filter.durationUnit:
  "min"/"perc") instead of a hardcoded "m".
- The Plex collection chip falls back to the "Collection" label, not the raw
  rating_key id, when collectionTitle is missing.
- Dropped the dead rowClassName that dimmed hidden rows in the subscribed table
  (hidden channels are excluded there now — they live in the Hidden tab).
- Renamed the misleading `set` null-check predicate to `has`.

Gate green: tsc/eslint-0/prettier/knip clean, vitest 106.

frontend/src/components/PlexBrowse.tsx

@@ -9,7 +9,7 @@ import {
   type ReactNode,
 } from "react";
 import { qk } from "../lib/queryKeys";
-import { healPlexSort, PLEX_SORT_FALLBACK } from "../lib/plexSort";
+import { healPlexSort } from "../lib/plexSort";
 import { createPortal } from "react-dom";
 import { useTranslation } from "react-i18next";
 import {
@@ -60,7 +60,7 @@ import PlexCollectionEditor from "./PlexCollectionEditor";
 import { LoadingState, StateMessage } from "./QueryState";
 import { PageToolbar } from "./PageShell";
 import ActiveFilterChips from "./ActiveFilterChips";
-import { usePlexActiveFilters } from "./usePlexActiveFilters";
+import { usePlexActiveFilters, usePlexClearFilters } from "./usePlexActiveFilters";
 import { usePlex, usePlexActions } from "./PlexProvider";
 
 // Lazy: the rich player (pulls in hls.js) loads only when something is first played.
@@ -91,16 +91,12 @@ export default function PlexBrowse() {
   // search term (q) comes from the shared header box; the rail hands off a playlist to open via the
   // shared `playlistOpen` slot, which we consume into a history subview then clear.
   const { q, scope, show, sort, filters, playlistOpen: openPlaylist } = usePlex();
-  const { setScope, setShow, setSort, setFilters, setPlaylistOpen } = usePlexActions();
+  const { setScope, setFilters, setPlaylistOpen } = usePlexActions();
   const dq = useDebounced(q.trim(), 350);
   // Plex's active-filter chip row (above the grid), the shared feed idiom: one removable chip per
-  // narrowing, plus a Clear-all that resets filters + watch-state + sort to their defaults.
+  // narrowing, plus a Clear-all (shared with the sidebar) that resets filters + watch-state + sort.
   const plexChips = usePlexActiveFilters();
-  const clearAllFilters = () => {
-    setFilters(EMPTY_PLEX_FILTERS);
-    setShow("all");
-    setSort(PLEX_SORT_FALLBACK);
-  };
+  const clearAllFilters = usePlexClearFilters();
   // The provider holds sort scope-agnostically; heal it against THIS scope's options so a movie-only
   // key (e.g. duration) left over from before a switch to shows doesn't ask for an unavailable sort.
   const sortState = healPlexSort(sort, scope);