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>

tests/core/test_tool_tracking.py

@@ -3,6 +3,7 @@ Tests for tool call tracking.
 
 Tests capability extraction and recommendation matching.
 """
+
 import pytest
 
 from src.core.tool_tracking import ToolCallTracker
@@ -29,9 +30,7 @@ class TestToolCallTracker:
     @pytest.mark.asyncio
     async def test_track_call_recognizes_delegation_as_recommended(self):
         """Test that delegate_to_X is recognized when X is recommended."""
-        tracker = ToolCallTracker(
-            recommended_capabilities=["librarian", "biographer"]
-        )
+        tracker = ToolCallTracker(recommended_capabilities=["librarian", "biographer"])
 
         await tracker.track_call("delegate_to_librarian", 1.0)
 
@@ -42,9 +41,7 @@ class TestToolCallTracker:
     @pytest.mark.asyncio
     async def test_track_call_detects_not_recommended(self):
         """Test that unrecommended tools are flagged."""
-        tracker = ToolCallTracker(
-            recommended_capabilities=["librarian"]
-        )
+        tracker = ToolCallTracker(recommended_capabilities=["librarian"])
 
         await tracker.track_call("delegate_to_housekeeper", 1.0)
 
@@ -55,9 +52,7 @@ class TestToolCallTracker:
 
     def test_get_summary_with_delegation_tools(self):
         """Test summary correctly maps delegation tools to capabilities."""
-        tracker = ToolCallTracker(
-            recommended_capabilities=["librarian", "biographer"]
-        )
+        tracker = ToolCallTracker(recommended_capabilities=["librarian", "biographer"])
         tracker.actual_calls = {
             "delegate_to_librarian": [1.0, 2.0],
             "delegate_to_housekeeper": [0.5],  # Not recommended
@@ -72,9 +67,7 @@ class TestToolCallTracker:
     @pytest.mark.asyncio
     async def test_finalize_with_delegation_tools(self):
         """Test finalize correctly identifies unused recommendations."""
-        tracker = ToolCallTracker(
-            recommended_capabilities=["librarian", "biographer"]
-        )
+        tracker = ToolCallTracker(recommended_capabilities=["librarian", "biographer"])
         tracker.actual_calls = {
             "delegate_to_librarian": [1.0],
         }