Claude-assisted improvements (untested)

- dev auth flow (side-step OAuth)
- db event processing integration tests
- dev scripts (eg Makefile)
- db / test db migration setup scripts.

database_migrations/000030_fix_oauth_tokens_schema_drift.down.sql

@@ -0,0 +1,14 @@
+BEGIN;
+
+ALTER TABLE oauth_tokens
+	ALTER COLUMN id_token_custom_claims_updated_at
+	TYPE TEXT
+	USING id_token_custom_claims_updated_at::TEXT;
+
+ALTER TABLE oauth_tokens
+	ADD COLUMN claims JSONB NOT NULL DEFAULT '{}'::jsonb;
+
+ALTER TABLE oauth_tokens
+	ALTER COLUMN claims DROP DEFAULT;
+
+COMMIT;