test(api): repair pre-existing rotted tests (SSE ticket flow, password policy)

These had been red since the changes they cover landed — invisible because
the pre-commit gate runs mypy/ruff/bandit/pip-audit but NOT pytest, so failing
tests don't block commits and quietly accumulate.

- SSE stream/events auth migrated from ?token=<jwt> to a single-use ?ticket=
  (commit efb4e49d). Three tests still passed a raw JWT as ?token= and got
  401. Updated to mint a ticket via POST /auth/sse-ticket and pass ?ticket=
  (attacker events, topology events, /stream).
- The user-creation password policy is min_length=12; the RBAC admin-access
  test still used a 10-char password and was rejected. Bumped to a valid one.

tests/api/test_rbac.py

@@ -39,7 +39,7 @@ async def test_admin_can_access_read_endpoints(client, auth_token, method, path)
 _ADMIN_ENDPOINTS = [
     ("PUT", "/api/v1/config/deployment-limit", {"deployment_limit": 5}),
     ("PUT", "/api/v1/config/global-mutation-interval", {"global_mutation_interval": "1d"}),
-    ("POST", "/api/v1/config/users", {"username": "rbac-test", "password": "pass123456", "role": "viewer"}),
+    ("POST", "/api/v1/config/users", {"username": "rbac-test", "password": "pass-123456789", "role": "viewer"}),
 ]