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/quality-picker.tsx

@@ -0,0 +1,40 @@
+interface QualityPickerProps {
+  quality: string;
+  options: { value: string; label: string }[];
+  showPicker: boolean;
+  onToggle: () => void;
+  onChangeQuality: (q: string) => void;
+}
+
+export function QualityPicker({
+  quality,
+  options,
+  showPicker,
+  onToggle,
+  onChangeQuality,
+}: QualityPickerProps) {
+  return (
+    <div className="pointer-events-auto relative">
+      <button
+        className="rounded-md bg-black/50 px-3 py-1.5 text-xs text-zinc-400 backdrop-blur transition-colors hover:bg-black/70 hover:text-white"
+        onClick={onToggle}
+        title="Stream quality"
+      >
+        {options.find((o) => o.value === quality)?.label ?? quality}
+      </button>
+      {showPicker && (
+        <div className="absolute right-0 top-9 z-30 min-w-[8rem] overflow-hidden rounded-md border border-zinc-700 bg-zinc-900/95 py-1 shadow-xl backdrop-blur">
+          {options.map((opt) => (
+            <button
+              key={opt.value}
+              className={`w-full px-3 py-1.5 text-left text-xs transition-colors hover:bg-zinc-700 ${quality === opt.value ? "text-white" : "text-zinc-400"}`}
+              onClick={() => onChangeQuality(opt.value)}
+            >
+              {opt.label}
+            </button>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}