style: apply ruff's automatic fixes and formatter

Mechanical only, and separated from the judgment calls that follow so the
reviewable changes are not buried in a 98-file whitespace diff.

227 automatic fixes: 60 blank lines carrying whitespace, 60 unsorted import
blocks, 34 Optional[X] to X | None, 28 unused imports, 16 deprecated typing
imports, 12 datetime.timezone.utc to datetime.UTC, and assorted smaller
modernisations. Then `ruff format` over src and tests: 98 files reformatted,
35 already conforming.

No file among the unused-import findings defines __all__ or is an __init__.py,
so nothing here removes a re-export.

`make test`: 658 passed, unchanged from HEAD.

Two things observed while verifying, neither addressed here:

`pytest tests/` cannot collect — tests/e2e/test_orchestration_e2e.py uses an
`e2e` marker that is not registered, and the config is strict about markers.
This fails identically at HEAD, so it predates this change; `make test` passes
because it ignores tests/e2e, tests/integration and tests/contracts.

test_tatlock_tool_call_logging_calculator is flaky. It failed once in a full run
with these changes and passed on the next, passes in isolation with them, and
fails in isolation at HEAD. It is order- or timing-dependent, not a regression
from this commit — established by running the full suite both ways rather than
by reasoning about which change could have caused it.

Co-Authored-By: Claude <noreply@anthropic.com>

src/agents/housekeeper/client.py

@@ -5,7 +5,8 @@ Provides async methods for home automation operations via Home Assistant.
 Core-API is a separate service that wraps the Home Assistant REST API
 into LLM-friendly endpoints.
 """
-from typing import Any, Optional
+
+from typing import Any
 
 import httpx
 from pydantic import BaseModel, Field
@@ -28,7 +29,7 @@ class Device(BaseModel):
     name: str
     state: str
     domain: str
-    area: Optional[str] = None
+    area: str | None = None
     attributes: dict[str, Any] = Field(default_factory=dict)
 
 
@@ -38,8 +39,8 @@ class DeviceState(BaseModel):
     entity_id: str
     state: str
     attributes: dict[str, Any] = Field(default_factory=dict)
-    last_changed: Optional[str] = None
-    last_updated: Optional[str] = None
+    last_changed: str | None = None
+    last_updated: str | None = None
 
 
 class Scene(BaseModel):
@@ -47,7 +48,7 @@ class Scene(BaseModel):
 
     entity_id: str
     name: str
-    friendly_name: Optional[str] = None
+    friendly_name: str | None = None
 
 
 class Script(BaseModel):
@@ -55,8 +56,8 @@ class Script(BaseModel):
 
     entity_id: str
     name: str
-    description: Optional[str] = None
-    last_triggered: Optional[str] = None
+    description: str | None = None
+    last_triggered: str | None = None
 
 
 class Automation(BaseModel):
@@ -64,8 +65,8 @@ class Automation(BaseModel):
 
     entity_id: str
     name: str
-    state: str  = "on"
-    last_triggered: Optional[str] = None
+    state: str = "on"
+    last_triggered: str | None = None
 
 
 class HistoryEntry(BaseModel):
@@ -109,8 +110,8 @@ class CoreAPIClient:
 
     def __init__(
         self,
-        base_url: Optional[str] = None,
-        api_key: Optional[str] = None,
+        base_url: str | None = None,
+        api_key: str | None = None,
         timeout: int = 30,
     ):
         """
@@ -124,7 +125,7 @@ class CoreAPIClient:
         self.base_url = base_url or str(config.CORE_API_HOST)
         self.api_key = api_key or config.CORE_API_KEY
         self.timeout = timeout
-        self._client: Optional[httpx.AsyncClient] = None
+        self._client: httpx.AsyncClient | None = None
 
     async def __aenter__(self) -> "CoreAPIClient":
         """Create HTTP client on context entry."""
@@ -159,8 +160,8 @@ class CoreAPIClient:
 
     async def list_devices(
         self,
-        domain: Optional[str] = None,
-        area: Optional[str] = None,
+        domain: str | None = None,
+        area: str | None = None,
     ) -> list[Device]:
         """
         List devices, optionally filtered by domain or area.
@@ -231,9 +232,9 @@ class CoreAPIClient:
     async def turn_on(
         self,
         entity_id: str,
-        brightness: Optional[int] = None,
-        color_temp: Optional[int] = None,
-        rgb_color: Optional[tuple[int, int, int]] = None,
+        brightness: int | None = None,
+        color_temp: int | None = None,
+        rgb_color: tuple[int, int, int] | None = None,
     ) -> ControlResult:
         """
         Turn on a device.
@@ -399,7 +400,7 @@ class CoreAPIClient:
     async def run_script(
         self,
         script_id: str,
-        variables: Optional[dict[str, Any]] = None,
+        variables: dict[str, Any] | None = None,
     ) -> ControlResult:
         """
         Run a script.