[chore] remove all remaining type:ignore suppressions from tests/

Converts 115 `# type: ignore[...]` suppressions across 23 test files to
no-suppression patterns (helper-return widening to Any, local Any aliases,
cc:Any aliases, cast at narrow call sites, typed fixtures) so the hard
no-type:ignore convention holds across tests/. No test logic or assertions
changed — only mock-wiring mechanics and type annotations.

Gate: ruff check tests/ clean; mypy tests/ (538 files) clean; 176 changed-file
tests pass. Zero real suppressions remain (the 7 grep hits are 3 hygiene-
checker string-literal test inputs and 4 prose mentions in comments).

tests/unit/services/test_services_base.py

@@ -2,6 +2,8 @@
 
 from __future__ import annotations
 
+from typing import Any, cast
+
 import pytest
 from roboco.services.base import (
     BaseService,
@@ -120,7 +122,7 @@ def test_base_service_binds_session_and_logger() -> None:
         service_name = "x"
 
     fake_session = object()
-    svc = _Svc(fake_session)  # type: ignore[arg-type]
+    svc = _Svc(cast("Any", fake_session))
     assert svc.session is fake_session
     assert svc.log is not None