Backend - V18 migration adds AGENT_LIFECYCLE to condition_kind_enum. Java ConditionKind enum shipped with this value but no Postgres migration extended the type, so any AGENT_LIFECYCLE rule insert failed with "invalid input value for enum condition_kind_enum". - ALTER TYPE ... ADD VALUE lives alone in its migration per Postgres constraint that the new value cannot be referenced in the same tx. - V18MigrationIT asserts the enum now contains all 7 kinds. Frontend - Add describeApiError(e) helper to unwrap openapi-fetch error bodies (Spring error JSON) into readable strings. String(e) on a plain object rendered "[object Object]" in toasts — the actual failure reason was hidden from the user. - Replace String(e) in all 13 toast descriptions across the alerting and outbound-connection mutation paths. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>