- Add recommended UnderlyingDB() usage pattern with examples - Document safety warnings (never close, no pool changes, keep txns short) - Add when to use UnderlyingDB() vs sql.Open() guidance - Update VC example to show embedding pattern with UnderlyingDB() - Cross-reference bd-64 safety requirements Closes bd-65 Amp-Thread-ID: https://ampcode.com/threads/T-c2c18266-ccf2-4615-a2f1-be134e8f1c0d Co-authored-by: Amp <amp@ampcode.com>