test: schema drift detection — PGLite must match Postgres columns

[garrytan-agents]

Schema drift detection: PGLite ↔ Postgres parity test

The bug (v0.26.1)

exchangeClientCredentials reads token_ttl from oauth_clients and the revoke endpoint writes deleted_at. Both columns were added via manual ALTER TABLE on production Postgres but never added to pglite-schema.ts. Result: all 35 unit tests (which use PGLite) broke with column "token_ttl" does not exist.

The fix was wrapping every new-column query in try/catch, which works but is fragile — the real fix is preventing the drift.

What we need

A CI test that compares schemas and fails if they diverge:

1. Table parity — every table in schema.sql + migrations exists in pglite-schema.ts
2. Column parity — every column on Postgres exists on PGLite with compatible types
3. Index parity — functionally-equivalent indexes exist on both
4. New column rule — any migration that adds a column to Postgres MUST also add it to pglite-schema.ts

Trigger

Run on every PR. Should catch drift BEFORE it ships.

Context

• Discovered during v0.26.1 admin dashboard work
• token_ttl, deleted_at on oauth_clients were production-only
• agent_name, params, error_message on mcp_request_log same pattern
• Current workaround: try/catch around every new-column query (fragile)