- es8311 driver open() now allows OUTPUT->INPUT complementary (promotes to BOTH) when same native rate 44100
- audio-stream close_stream() ref-counts shared BOTH codec (don't close if other direction still open)
- MCP recordVoice + VoiceRecorder app explicitly unmute and set 100% gain
Fixes mic input not working - was returning ERROR_RESOURCE when output already open
- Restore MCP system (McpSystem 1900+ LOC, McpHandler, McpScreensaver, McpSettings, McpOverride apps)
- Use audio-stream instead of direct I2S for MP3 playback (fixes fast playback, uses native resampler)
- Register McpSettings + McpOverride in Tactility.cpp so Settings shows MCP Screen
- DisplaySettings: add ScreensaverType::McpScreen and disableScreensaverWhenCharging flag
- Display app: add 'Disable on charging' toggle, handles McpScreen screensaver type
- DisplayIdle: skip screensaver while charging, support McpScreen screensaver, isDeviceCharging check via PowerDevice
- WebServer: coexistence with MCP (McpHandler)
- Avoid formatting churn from previous commits
Squashed from range eaa248b0..8970143f (6 commits) into single clean commit