Fixes 'invalid input syntax for type uuid' error when writing ticket
workflow audit logs. The audit Event.ID field was using fmt.Sprintf
with nanoseconds ('wf-%d') which doesn't match PostgreSQL's uuid type.
Also adds uuid import to ticket_workflow.go.
Verified: full chain webhook→assign→resolve→close produces 3 audit
logs correctly, no more 'invalid uuid' errors in logs.
1. config.go: AI_CS_ENV runtime mode with production restriction
- New RuntimeConfig.Env field (AI_CS_ENV / AI_CS_RUNTIME_ENV)
- production + Postgres.Enabled=false → Load() returns error
- production + empty webhook secret → Load() returns error
- normalizeRuntimeEnv: dev/dev/ → development, prod/production → production, test → test
2. app.go: probe.SetReady only when store is confirmed ready
- Postgres.Enabled: probe.SetReady(true) after DB+migration OK
- Memory mode: probe.SetReady(false) — not production-ready
3. health_handler_test.go: add probe live+ready state transition tests
4. config_test.go: add TestLoad_RejectsProdWhenPostgresDisabled,
TestLoad_RejectsProdWhenWebhookSecretMissing
5. app_test.go: add TestNew_RejectsMemoryModeWithoutExplicitNonProdEnv,
TestNew_AllowsMemoryModeInTestEnv, TestNew_WithPostgresEnabled_*
for invalid DSN and migration-failure paths
Phase 1 (code gate) objectives met:
✅ prod cannot fall back to memory store
✅ readiness reflects actual store readiness
✅ both changes have test coverage
