fix: enforce atomic agent registration contract

packages/server/migrations/002_agent_integration_contract.sql

@@ -0,0 +1,28 @@
+-- Require every agent to declare a supported integration type.
+
+BEGIN;
+
+ALTER TABLE agents
+  ALTER COLUMN integration_type DROP DEFAULT;
+
+ALTER TABLE agents
+  DROP CONSTRAINT IF EXISTS agents_integration_type_check;
+
+ALTER TABLE agents
+  ADD CONSTRAINT agents_integration_type_check
+  CHECK (integration_type IN (
+    'augment', 'claudecode', 'cline', 'codex', 'copilot',
+    'cursor', 'droid', 'gemini', 'grok', 'kimi', 'kirocli',
+    'kiroide', 'letta', 'opencode', 'qwen', 'enterprise',
+    'gui', 'sdk', 'other'
+  ));
+
+INSERT INTO schema_versions (version, applied_at, description)
+VALUES (
+  2,
+  EXTRACT(EPOCH FROM NOW())::BIGINT * 1000,
+  'Require a supported agent integration type'
+)
+ON CONFLICT (version) DO NOTHING;
+
+COMMIT;