[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/runtime/test_readopt_running_agents.py

@@ -12,6 +12,7 @@ reaper's live-skip and the spawn gate see the live agent immediately.
 
 from __future__ import annotations
 
+from typing import Any
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest
@@ -20,7 +21,7 @@ from roboco.runtime.orchestrator import AgentOrchestrator, AgentState
 _EXPECTED_READOPTED = 2
 
 
-def _orch() -> AgentOrchestrator:
+def _orch() -> Any:
     orch = AgentOrchestrator.__new__(AgentOrchestrator)  # bypass __init__
     orch._instances = {}
     return orch
@@ -35,7 +36,7 @@ async def test_readopts_running_containers_as_active() -> None:
         slug = name.removeprefix("roboco-agent-")
         return (slug in running, 0)
 
-    orch._inspect_container_state = AsyncMock(side_effect=inspect)  # type: ignore[method-assign]
+    orch._inspect_container_state = AsyncMock(side_effect=inspect)
 
     n = await orch._readopt_running_agents()
 
@@ -51,7 +52,7 @@ async def test_readopt_leaves_already_tracked_instance_untouched() -> None:
     orch = _orch()
     sentinel = MagicMock()
     orch._instances = {"be-dev-1": sentinel}
-    orch._inspect_container_state = AsyncMock(return_value=(True, 0))  # type: ignore[method-assign]
+    orch._inspect_container_state = AsyncMock(return_value=(True, 0))
 
     await orch._readopt_running_agents()
 
@@ -61,7 +62,7 @@ async def test_readopt_leaves_already_tracked_instance_untouched() -> None:
 @pytest.mark.asyncio
 async def test_readopt_inert_when_nothing_running() -> None:
     orch = _orch()
-    orch._inspect_container_state = AsyncMock(return_value=(False, None))  # type: ignore[method-assign]
+    orch._inspect_container_state = AsyncMock(return_value=(False, None))
 
     n = await orch._readopt_running_agents()
 
@@ -72,7 +73,7 @@ async def test_readopt_inert_when_nothing_running() -> None:
 @pytest.mark.asyncio
 async def test_readopt_swallows_probe_errors() -> None:
     orch = _orch()
-    orch._inspect_container_state = AsyncMock(side_effect=RuntimeError("no docker"))  # type: ignore[method-assign]
+    orch._inspect_container_state = AsyncMock(side_effect=RuntimeError("no docker"))
 
     n = await orch._readopt_running_agents()
 
@@ -87,8 +88,8 @@ async def test_readopt_records_container_id_so_health_check_can_see_exit() -> No
     # is stranded under a phantom ACTIVE instance forever. Re-adopt must capture
     # the real container id so the health loop can observe the later exit.
     orch = _orch()
-    orch._inspect_container_state = AsyncMock(return_value=(True, 0))  # type: ignore[method-assign]
-    orch._resolve_container_id = AsyncMock(return_value="deadbeef1234")  # type: ignore[method-assign]
+    orch._inspect_container_state = AsyncMock(return_value=(True, 0))
+    orch._resolve_container_id = AsyncMock(return_value="deadbeef1234")
 
     await orch._readopt_running_agents()