Gmail - Maton API

Executable playbook for interacting with Gmail REST v1 and Google Drive REST v3 through the Maton API bridge using OAuth 2.0 (OOB or 3‑legged). Includes prerequisites (Google Cloud Console API enablement), OAuth handshake geometry, non-destructive Gmail message/thread retrieval & label management, and Drive v3 metadata/file discovery. Enforces zero-PII and secret-redaction constraints.