feat: add server-sent events for logging and activity tracking

- Implemented a custom tracing layer (`AppLogLayer`) to capture log events and broadcast them to SSE clients.
- Created admin routes for streaming server logs and listing recent activity logs.
- Added an activity log repository interface and SQLite implementation for persisting activity events.
- Integrated activity logging into user authentication and channel CRUD operations.
- Developed frontend components for displaying server logs and activity logs in the admin panel.
- Enhanced the video player with a stats overlay for monitoring streaming metrics.

k-tv-frontend/app/(main)/tv/components/video-player.tsx

@@ -1,6 +1,8 @@
 import { forwardRef, useEffect, useRef, useState } from "react";
 import Hls from "hls.js";
 import { Loader2 } from "lucide-react";
+import type { CurrentBroadcastResponse } from "@/lib/types";
+import { StatsPanel } from "./stats-panel";
 
 export interface SubtitleTrack {
   id: number;
@@ -19,6 +21,10 @@ interface VideoPlayerProps {
   muted?: boolean;
   /** Force direct-file mode (skips hls.js even for .m3u8 URLs). */
   streamingProtocol?: "hls" | "direct_file";
+  /** When true, renders the Stats for Nerds overlay. */
+  showStats?: boolean;
+  /** Current broadcast data passed to the stats panel for slot timing. */
+  broadcast?: CurrentBroadcastResponse | null;
   onStreamError?: () => void;
   onSubtitleTracksChange?: (tracks: SubtitleTrack[]) => void;
   /** Called when the browser blocks autoplay and user interaction is required. */
@@ -37,6 +43,8 @@ const VideoPlayer = forwardRef<HTMLVideoElement, VideoPlayerProps>(
       subtitleTrack = -1,
       muted = false,
       streamingProtocol,
+      showStats = false,
+      broadcast,
       onStreamError,
       onSubtitleTracksChange,
       onNeedsInteraction,
@@ -162,6 +170,16 @@ const VideoPlayer = forwardRef<HTMLVideoElement, VideoPlayerProps>(
             <Loader2 className="h-10 w-10 animate-spin text-zinc-500" />
           </div>
         )}
+
+        {/* Stats for Nerds overlay */}
+        {showStats && (
+          <StatsPanel
+            videoRef={internalRef}
+            hlsRef={hlsRef}
+            streamingProtocol={streamingProtocol}
+            broadcast={broadcast}
+          />
+        )}
       </div>
     );
   },