feat(transcoding): add FFmpeg HLS transcoding support

- Introduced `TranscodeManager` for managing on-demand transcoding of local video files.
- Added configuration options for transcoding in `Config` and `LocalFilesConfig`.
- Implemented new API routes for managing transcoding settings, stats, and cache.
- Updated `LocalFilesProvider` to support transcoding capabilities.
- Created frontend components for managing transcode settings and displaying stats.
- Added database migration for transcode settings.
- Enhanced existing routes and DTOs to accommodate new transcoding features.

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

@@ -1,7 +1,7 @@
 "use client";
 
 import { useState, useEffect } from "react";
-import { Plus, Upload, RefreshCw, Antenna } from "lucide-react";
+import { Plus, Upload, RefreshCw, Antenna, Settings2 } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import {
   useChannels,
@@ -26,6 +26,7 @@ import {
   type ChannelImportData,
 } from "./components/import-channel-dialog";
 import { IptvExportDialog } from "./components/iptv-export-dialog";
+import { TranscodeSettingsDialog } from "./components/transcode-settings-dialog";
 import type {
   ChannelResponse,
   ProgrammingBlock,
@@ -112,6 +113,7 @@ export default function DashboardPage() {
   };
 
   const [iptvOpen, setIptvOpen] = useState(false);
+  const [transcodeOpen, setTranscodeOpen] = useState(false);
   const [createOpen, setCreateOpen] = useState(false);
   const [importOpen, setImportOpen] = useState(false);
   const [importPending, setImportPending] = useState(false);
@@ -231,6 +233,16 @@ export default function DashboardPage() {
           </p>
         </div>
         <div className="flex gap-2">
+          {config?.providers?.some((p) => p.capabilities.transcode) && (
+            <Button
+              onClick={() => setTranscodeOpen(true)}
+              title="Transcode settings"
+              className="border-zinc-700 text-zinc-400 hover:text-zinc-100"
+            >
+              <Settings2 className="size-4" />
+              Transcode
+            </Button>
+          )}
           {capabilities?.rescan && (
             <Button
               onClick={() =>
@@ -329,6 +341,11 @@ export default function DashboardPage() {
       )}
 
       {/* Dialogs / sheets */}
+      <TranscodeSettingsDialog
+        open={transcodeOpen}
+        onOpenChange={setTranscodeOpen}
+      />
+
       {token && (
         <IptvExportDialog
           open={iptvOpen}