fix(gateway): enforce server-side model policy

[winrey]

Summary

• make the Team9 gateway the authoritative allowlist for staff model creation and mutation
• reject fixed base-model bots and unsupported provider/model pairs before persistence or dispatch
• persist durable model-change decisions and dispatch through an idempotent PostgreSQL outbox
• expose the authenticated server catalog and update the client for pending model changes
• align the integration with current agent-pi: use caller-provided messageId and remove the obsolete /api/workers/readiness dependency

Security and operations

• bounded audit values and low-cardinality metrics; no request bodies, credentials, or prompts in logs
• migrations 0066_model_change_attempts.sql and 0067_model_change_publication.sql
• rollout runbook keeps the outbox disabled until the deployed agent-pi build passes model-registry and idempotency smokes

Verification

• pnpm check:migrations — 68 migrations passed
• pnpm lint:ci — passed with 32 existing warnings and 0 errors
• pnpm build — 17/17 tasks passed
• Gateway — 190 files, 3587 tests passed
• Client — 233 files, 2724 tests passed
• Database — 7 suites, 21 tests passed with required test DB environment values
• claw-hive client — 45 tests passed
• focused model-policy regression set — 242 tests passed

The root pnpm test command still exposes an existing nested-Turbo environment-filtering issue in seed.spec.ts; that file is unchanged from dev, and the database suite passes when its documented required variables are supplied.