fix(tests): resolve pyright errors in stale-check test files

Remove unused imports, add missing type annotations, fix Die()
constructor calls (int code, not str), replace fake backend
subclass with patch.object approach to avoid reportMissingParameterType
and override-incompatibility errors in strict pyright mode.

tests/unit/test_macos_container_launch.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import dataclasses
 import unittest
 import tempfile
 from pathlib import Path
@@ -15,6 +16,7 @@ from bot_bottle.backend.macos_container import launch
 from bot_bottle.backend.macos_container.bottle_plan import MacosContainerBottlePlan
 from bot_bottle.egress import EgressPlan
 from bot_bottle.git_gate import GitGatePlan
+from bot_bottle.log import Die
 from bot_bottle.manifest import ManifestIndex
 
 _MANIFEST = ManifestIndex.from_json_obj({
@@ -373,17 +375,16 @@ class TestMacosContainerLaunchCachedImages(unittest.TestCase):
     def tearDown(self):
         self._tmp.cleanup()
 
-    def test_cached_mode_dies_when_agent_image_missing(self):
-        plan = _build_plan(self.stage_dir)
-        from bot_bottle.backend import BottleSpec
-        import dataclasses
-        plan = dataclasses.replace(
-            plan,
+    def _cached_plan(self) -> MacosContainerBottlePlan:
+        return dataclasses.replace(
+            _build_plan(self.stage_dir),
             spec=cast(BottleSpec, SimpleNamespace(image_policy="cached")),
         )
-        from bot_bottle.log import Die
 
-        def image_exists(ref: str) -> bool:
+    def test_cached_mode_dies_when_agent_image_missing(self) -> None:
+        plan = self._cached_plan()
+
+        def image_exists(ref: str) -> bool:  # pylint: disable=unused-argument
             return False  # Nothing cached.
 
         with patch.object(
@@ -391,43 +392,29 @@ class TestMacosContainerLaunchCachedImages(unittest.TestCase):
         ), patch.object(
             launch.container_mod, "image_exists", side_effect=image_exists,
         ), patch.object(
-            launch, "die", side_effect=Die("no agent image"),
+            launch, "die", side_effect=Die(),
         ):
             with self.assertRaises(Die):
                 launch._build_images(plan)
 
-    def test_cached_mode_dies_when_sidecar_image_missing(self):
-        plan = _build_plan(self.stage_dir)
-        from bot_bottle.backend import BottleSpec
-        import dataclasses
-        plan = dataclasses.replace(
-            plan,
-            spec=cast(BottleSpec, SimpleNamespace(image_policy="cached")),
-        )
-        from bot_bottle.log import Die
+    def test_cached_mode_dies_when_sidecar_image_missing(self) -> None:
+        plan = self._cached_plan()
 
         def image_exists(ref: str) -> bool:
-            # Agent image is present; sidecar is missing.
-            return ref == plan.image
+            return ref == plan.image  # Agent present; sidecar missing.
 
         with patch.object(
             launch, "read_committed_image", return_value="",
         ), patch.object(
             launch.container_mod, "image_exists", side_effect=image_exists,
         ), patch.object(
-            launch, "die", side_effect=Die("no sidecar image"),
+            launch, "die", side_effect=Die(),
         ):
             with self.assertRaises(Die):
                 launch._build_images(plan)
 
-    def test_cached_mode_both_present_returns_unchanged_plan(self):
-        plan = _build_plan(self.stage_dir)
-        from bot_bottle.backend import BottleSpec
-        import dataclasses
-        plan = dataclasses.replace(
-            plan,
-            spec=cast(BottleSpec, SimpleNamespace(image_policy="cached")),
-        )
+    def test_cached_mode_both_present_returns_unchanged_plan(self) -> None:
+        plan = self._cached_plan()
         with patch.object(
             launch, "read_committed_image", return_value="",
         ), patch.object(
@@ -440,14 +427,8 @@ class TestMacosContainerLaunchCachedImages(unittest.TestCase):
         build.assert_not_called()
         self.assertEqual(plan.image, result.image)
 
-    def test_committed_image_plus_cached_skips_sidecar_build(self):
-        plan = _build_plan(self.stage_dir)
-        from bot_bottle.backend import BottleSpec
-        import dataclasses
-        plan = dataclasses.replace(
-            plan,
-            spec=cast(BottleSpec, SimpleNamespace(image_policy="cached")),
-        )
+    def test_committed_image_plus_cached_skips_sidecar_build(self) -> None:
+        plan = self._cached_plan()
         with patch.object(
             launch, "read_committed_image",
             return_value="bot-bottle-committed-dev-abc:latest",