feat(moneo): add recorder — single-file continuous WAV file capture to SD

[Ricky1207-sen]

Adds moneo/Recorder — captures audio into a single continuous WAV
file on the SD card (no chunk files).

• Touch to start/stop; LED indicates recording.
• Capture task fills a PSRAM buffer; a writer task flushes it to the
  WAV file every segment (default 10s) in the background.
• WAV header is finalized with the correct length on stop.
• Files named by datetime (rec_YYYYMMDD_HHMMSS.wav) via NTP, with a
  millis-based fallback if the clock isn't synced.
• 8-bit / 16kHz mono. Builds on the Config.h added earlier.