[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/integration/test_migration_014_drop_pm_approvals.py

@@ -7,12 +7,17 @@ tracking, RAG context). Only pm_approvals is truly orphaned.
 
 from __future__ import annotations
 
+from typing import TYPE_CHECKING
+
 import pytest
 from sqlalchemy import text
 
+if TYPE_CHECKING:
+    from sqlalchemy.ext.asyncio import AsyncSession
+
 
 @pytest.mark.asyncio
-async def test_pm_approvals_dropped(db_session) -> None:  # type: ignore[no-untyped-def]
+async def test_pm_approvals_dropped(db_session: AsyncSession) -> None:
     """pm_approvals column is gone from the tasks table."""
     result = await db_session.execute(
         text(
@@ -25,7 +30,9 @@ async def test_pm_approvals_dropped(db_session) -> None:  # type: ignore[no-unty
 
 
 @pytest.mark.asyncio
-async def test_quick_context_and_proactive_context_remain(db_session) -> None:  # type: ignore[no-untyped-def]
+async def test_quick_context_and_proactive_context_remain(
+    db_session: AsyncSession,
+) -> None:
     """quick_context and proactive_context MUST remain — they're actively used."""
     result = await db_session.execute(
         text(