Resolve OQ-01 through OQ-10 with formal ADRs and update all architecture
docs to reference decisions. Add two new tracked questions (OQ-11, OQ-12)
surfaced during review.
ADR-009: Keep FooRelations naming convention for relation entries
ADR-010: One module per database, include derived schemas by default
ADR-011: Support JSX/TSX as ergonomic authoring layer
ADR-012: Always .returning() with graceful fallback per dialect
ADR-013: Adapter generates relations from module entries (no <relation> element)
ADR-014: Leverage drizzle-kit for migrations, no native migration generator
Also upgrades elements.md, hosts.md, repo-adapter.md status to stable,
clarifies OQ-06 as design clarification, and specifies MySQL .returning()
detection mechanism in ADR-012.