feat(config): unify mpv plugin options under main config and add CSS/Ani

- Replace subminer.conf plugin config with mpv.* fields in config.jsonc
- Add socketPath, backend, autoStartSubMiner, pauseUntilOverlayReady, aniskipEnabled/buttonKey, subminerBinaryPath to mpv config
- Add subtitleSidebar.css field; migrate legacy sidebar appearance fields
- Add paintOrder and WebkitTextStroke to subtitle style options
- Update default subtitle/sidebar fontFamily to CJK-first stack
- Fix overlay visible state surviving mpv y-r restart
- Fix live config saves applying subtitle CSS immediately to open overlays
- Migrate legacy primary/secondary subtitle appearance into subtitleStyle.css on load
- Switch AniSkip button key setting to click-to-learn key capture

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

@@ -25,6 +25,7 @@ type AnilistPostWatchRunOptions = {
 export function createBindMpvMainEventHandlersHandler(deps: {
   reportJellyfinRemoteStopped: () => void;
   syncOverlayMpvSubtitleSuppression: () => void;
+  onMpvConnected?: () => void;
   resetSubtitleSidebarEmbeddedLayout: () => void;
   scheduleCharacterDictionarySync?: () => void;
   hasInitialPlaybackQuitOnDisconnectArg: () => boolean;
@@ -83,6 +84,7 @@ export function createBindMpvMainEventHandlersHandler(deps: {
       reportJellyfinRemoteStopped: () => deps.reportJellyfinRemoteStopped(),
       refreshDiscordPresence: () => deps.refreshDiscordPresence(),
       syncOverlayMpvSubtitleSuppression: () => deps.syncOverlayMpvSubtitleSuppression(),
+      onConnected: () => deps.onMpvConnected?.(),
       hasInitialPlaybackQuitOnDisconnectArg: () => deps.hasInitialPlaybackQuitOnDisconnectArg(),
       isOverlayRuntimeInitialized: () => deps.isOverlayRuntimeInitialized(),
       shouldQuitOnDisconnectWhenOverlayRuntimeInitialized: () =>