refactor(frontend): extract logic to hooks, split inline components

Area 1 (tv/page.tsx 964→423 lines):
- hooks: use-fullscreen, use-idle, use-volume, use-quality, use-subtitles,
  use-channel-input, use-channel-passwords, use-tv-keyboard
- components: SubtitlePicker, VolumeControl, QualityPicker, TopControlBar,
  LogoWatermark, AutoplayPrompt, ChannelNumberOverlay, TvBaseLayer

Area 2 (edit-channel-sheet.tsx 1244→678 lines):
- hooks: use-channel-form (all form state + reset logic)
- lib/schemas.ts: extracted Zod schemas + extractErrors
- components: AlgorithmicFilterEditor, RecyclePolicyEditor, WebhookEditor,
  AccessSettingsEditor, LogoEditor

Area 3 (dashboard/page.tsx 406→261 lines):
- hooks: use-channel-order, use-import-channel, use-regenerate-all
- lib/channel-export.ts: pure export utility
- components: DashboardHeader

k-tv-frontend/app/(main)/tv/components/index.ts

@@ -18,3 +18,12 @@ export { NoSignal } from "./no-signal";
 export type { NoSignalProps, NoSignalVariant } from "./no-signal";
 
 export { ChannelPasswordModal } from "./channel-password-modal";
+
+export { SubtitlePicker } from "./subtitle-picker";
+export { VolumeControl } from "./volume-control";
+export { QualityPicker } from "./quality-picker";
+export { TopControlBar } from "./top-control-bar";
+export { LogoWatermark } from "./logo-watermark";
+export { AutoplayPrompt } from "./autoplay-prompt";
+export { ChannelNumberOverlay } from "./channel-number-overlay";
+export { TvBaseLayer } from "./tv-base-layer";