Add VoiceNotes firmware and CDM customer service SQL project

VoiceNotes is an Arduino sketch for the Waveshare ESP32-C6-LCD-0.85 that
records meetings and voice memos to microSD and turns them into notes:

- Records 16 kHz mono WAV (up to 4 h) from the ES7210 dual mics, with a
  boosted preamp and soft-limited digital gain
- Transcribes via an OpenAI-compatible speech-to-text API in ~10 min parts
  cut at quiet points, with retries and resume after failures
- Summarizes the transcript with Claude into meeting notes (decisions,
  action items, topics with timestamps), streamed to and from the card
- Copies the notes to Nextcloud over WebDAV
- Shows recording/processing state on the 0.85" LCD and the LED ring
- Works around the board's SD card failing multi-sector reads

Credentials live in VoiceNotes/secrets.h, which is git-ignored; see
secrets.example.h.

Also adds the Microsoft CDM customer service SQL implementation (DDL,
sample data, reporting queries and docs). Its README is renamed to
CDM_README.md so the repository README stays at the top level.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

VoiceNotes/cloud.h

@@ -0,0 +1,6 @@
+// Speech-to-text + Claude summary pipeline. Runs in its own FreeRTOS task so
+// the display and LED ring keep animating while the network calls block.
+#pragma once
+
+bool cloudStart(const char *wavPath);  // false if a job is already running
+bool cloudBusy();