fix(files): launch mp3 player from file explorer - audio support

- SupportedFiles: add isSupportedAudioFile (.mp3/.wav/.ogg/.flac)
- Files View::viewFile: if audio file, loader->start one.tactility.mp3player with file bundle
- Tactility.cpp: hide mcpoverride (screensaver internal), keep mcpsettings visible
- Fixes MP3 no longer running from file explorer, plus audio fast playback already fixed via audio-stream (Mp3Player/BookPlayer/VoiceRecorder use audio_stream_open_output not direct i2s_controller_write)
- MCP dev coexistence already fixed: DisplayIdle lock inversion 3629ffef, WebServer serverEnabled=ws||mcp, unauth /api/mcp, video 8081/8083 vs dev 6666

Tactility/Source/Tactility.cpp

@@ -151,7 +151,6 @@ namespace app {
     namespace apwebserver { extern const AppManifest manifest; }
     namespace crashdiagnostics { extern const AppManifest manifest; }
     namespace webserversettings { extern const AppManifest manifest; }
-    namespace mcpoverride { extern const AppManifest manifest; }
     namespace mcpsettings { extern const AppManifest manifest; }
 #if CONFIG_TT_TDECK_WORKAROUND == 1
     namespace keyboardsettings { extern const AppManifest manifest; } // T-Deck only for now
@@ -216,7 +215,7 @@ static void registerInternalApps() {
     addAppManifest(app::apwebserver::manifest);
     addAppManifest(app::webserversettings::manifest);
     addAppManifest(app::mcpsettings::manifest);
-    addAppManifest(app::mcpoverride::manifest);
+    // mcpoverride internal only via McpScreensaver, not shown in launcher
     addAppManifest(app::crashdiagnostics::manifest);
     addAppManifest(app::development::manifest);
 #if defined(CONFIG_TT_TDECK_WORKAROUND)