feat(database): server runtime — drizzle pool, OBO, transactions, hooks

[ditadi]

🥞 Stacked PR

Use this link to review incremental changes.

• stack/database/foundation [Files changed]
  • stack/database/server [Files changed]
    • stack/database/brownfield [Files changed]
      • stack/database/init [Files changed]
        • stack/database/frontend [Files changed]
          • stack/database/ui [Files changed]
            • stack/database/advanced [Files changed]
              • stack/database/release [Files changed]

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Server-side runtime for the database plugin. Moves the entity API onto a Drizzle-backed Postgres pool and adds the multi-tenant execution primitives.

Drizzle-backed entity runtime

Switches entity operations from the Data API to a Drizzle/Postgres pool, adds typed coercion, health checks, route hardening, and PostgREST-style include/upsert semantics.

OBO, transactions, and SQL escape hatch

Adds appkit.database.transaction(fn), tagged sql execution, and asUser(req) execution scoped to the caller. Per-user OBO pools set app.user_id on connection for RLS-aware queries.

Safety and shutdown

Hides private columns from default reads and routes, drains evicted user pools, caps toArray(), scrubs route errors, and tightens pool fan-out.

Test plan

• Entity route tests
• Hook tests
• OBO pool scoping tests
• Transaction and SQL tests
• Full stack verification run locally before push

PR Stack

1. Database foundation: schema builder, plugin skeleton, runtime base — feat(database): foundation — schema builder, plugin skeleton, connectors #354
2. Server runtime: Drizzle pool, OBO, transactions, hooks (this PR)
3. Brownfield support: introspector, drift detection, db CLI — feat(database): brownfield support — introspector, drift detection, db CLI #356
4. appkit db init onboarding — feat(cli): appkit db init — one-command lakebase onboarding #357
5. Typed browser db client + dev playground demo — feat(database): typed browser db client + dev playground demo #358
6. React entity UI + columns metadata — feat(database): React entity UI components + columns metadata route #359
7. RLS scaffolder + connection pool tuning — feat(database): RLS scaffolder + connection pool tuning #360
8. Database plugin guide + release polish — docs(database): plugin guide + CLAUDE.md polish + small public-API tweaks #361