# Teleon 18-Database Shared Backend & Stateless Surface Contract

1. **18 Database Units (`DB-UNIT-01 .. DB-UNIT-18`)**: Acquire (`11`), Interrogate & Scenarios (`12`), Solve & Compose (`13`, `04`), Describe & Index (`02`, `14`), Serve & Telemetry (`03`, `06`, `07`), and Governance/Settlement (`01`, `05`, `08`, `09`, `10`, `15..18`).
2. **Dual-Track Execution**: Track 1 (`q01..q21`) processes operational work via 0-call deterministic operators or AI agents; Track 2 Sister (`sq01..sq18`) proposes and holdout-verifies self-tuning upgrades.
3. **Substrate Exemption (`EXEMPT_DATABASE_SUBSTRATES`)**: Cellular `*-db.teleon.dev` pools enforce `max_inline_steps = 0` so agent wrappers never block ACID transactions.
4. **Stateless Surfaces (`X-Teleon-Surface-Id` + THP v1.0)**: Independent web and agent surfaces share D1 (`teleon-core-fabric`) and R2 (`teleon-universal-cas`) while isolating surface-specific tables (`surface_<slug>_*`).