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/hooks/use-channel-order.ts

@@ -0,0 +1,53 @@
+"use client";
+
+import { useState, useEffect } from "react";
+import type { ChannelResponse } from "@/lib/types";
+
+export function useChannelOrder(channels: ChannelResponse[] | undefined) {
+  const [channelOrder, setChannelOrder] = useState<string[]>([]);
+
+  useEffect(() => {
+    try {
+      const stored = localStorage.getItem("k-tv-channel-order");
+      if (stored) setChannelOrder(JSON.parse(stored));
+    } catch {}
+  }, []);
+
+  const saveOrder = (order: string[]) => {
+    setChannelOrder(order);
+    try {
+      localStorage.setItem("k-tv-channel-order", JSON.stringify(order));
+    } catch {}
+  };
+
+  const sortedChannels = channels
+    ? [...channels].sort((a, b) => {
+        const ai = channelOrder.indexOf(a.id);
+        const bi = channelOrder.indexOf(b.id);
+        if (ai === -1 && bi === -1) return 0;
+        if (ai === -1) return 1;
+        if (bi === -1) return -1;
+        return ai - bi;
+      })
+    : [];
+
+  const handleMoveUp = (channelId: string) => {
+    const ids = sortedChannels.map((c) => c.id);
+    const idx = ids.indexOf(channelId);
+    if (idx <= 0) return;
+    const next = [...ids];
+    [next[idx - 1], next[idx]] = [next[idx], next[idx - 1]];
+    saveOrder(next);
+  };
+
+  const handleMoveDown = (channelId: string) => {
+    const ids = sortedChannels.map((c) => c.id);
+    const idx = ids.indexOf(channelId);
+    if (idx === -1 || idx >= ids.length - 1) return;
+    const next = [...ids];
+    [next[idx], next[idx + 1]] = [next[idx + 1], next[idx]];
+    saveOrder(next);
+  };
+
+  return { channelOrder, sortedChannels, handleMoveUp, handleMoveDown };
+}