feat(stats): wire stats server, overlay, and CLI into main process

- Stats server auto-start on immersion tracker init
- Stats overlay toggle via keybinding and IPC
- Stats CLI command (subminer stats) with cleanup mode
- mpv plugin menu integration for stats toggle
- CLI args for --stats, --stats-cleanup, --stats-response-path

src/main/runtime/mpv-main-event-bindings.ts

@@ -57,6 +57,7 @@ export function createBindMpvMainEventHandlersHandler(deps: {
   notifyImmersionTitleUpdate: (title: string) => void;
 
   recordPlaybackPosition: (time: number) => void;
+  recordMediaDuration: (durationSec: number) => void;
   reportJellyfinRemoteProgress: (forceImmediate: boolean) => void;
   recordPauseState: (paused: boolean) => void;
 
@@ -147,6 +148,7 @@ export function createBindMpvMainEventHandlersHandler(deps: {
       onMediaPathChange: handleMpvMediaPathChange,
       onMediaTitleChange: handleMpvMediaTitleChange,
       onTimePosChange: handleMpvTimePosChange,
+      onDurationChange: ({ duration }) => deps.recordMediaDuration(duration),
       onPauseChange: handleMpvPauseChange,
       onSubtitleMetricsChange: handleMpvSubtitleMetricsChange,
       onSecondarySubtitleVisibility: handleMpvSecondarySubtitleVisibility,