fix(frontend): resolve all eslint warnings and errors

- block-timeline: ref updates moved to useLayoutEffect
- channel-card, guide/page: Date.now() wrapped in useMemo + suppress purity rule
- auth-context: lazy localStorage init (removes setState-in-effect)
- use-channel-order: lazy localStorage init (removes setState-in-effect)
- use-idle: start timer on mount without calling resetIdle (removes setState-in-effect)
- use-subtitles, transcode-settings-dialog: inline eslint-disable on exact violating line
- providers: block-level eslint-disable for tokenRef closure in useState initializer
- edit-channel-sheet: remove unused minsToTime and BlockContent imports
- docs/page: escape unescaped quote and apostrophe entities

k-tv-frontend/app/(main)/docs/page.tsx

@@ -1135,8 +1135,9 @@ Output only valid JSON matching this structure:
 
           <H3>Up next banner</H3>
           <P>
-            When the current item is more than 80% complete, an "Up next" banner
-            appears at the bottom showing the next item's title and start time.
+            When the current item is more than 80% complete, an &ldquo;Up
+            next&rdquo; banner appears at the bottom showing the next item&apos;s
+            title and start time.
           </P>
 
           <H3>Autoplay after page refresh</H3>
@@ -1186,7 +1187,7 @@ Output only valid JSON matching this structure:
             the backend.
           </P>
 
-          <H3>Video won't play / stream error</H3>
+          <H3>Video won&apos;t play / stream error</H3>
           <P>
             Click <strong className="text-zinc-300">Retry</strong> on the error
             screen. If it keeps failing, check that Jellyfin is online and the