Repair the pre-commit quality gate and clear the ruff backlog

The pre-commit hooks declared `language: system` with bare `ruff`/`ty`
entries, but both are uv-managed dev dependencies and are not on PATH, so every
commit failed with `Executable 'ruff' not found`. Route both through
`uv run`; keep ruff blocking and make ty advisory (verbose) until its 18
whole-project diagnostics are cleared.

With the gate working, clear `ruff check .` to zero:

- 18 auto-fixes (import sorting, blank lines, `max()` simplification,
  `with` merging, unused imports).
- Real defects: `SourceNavigation` annotated but never imported in
  sources_page; two naive `datetime.now()` calls in migration.py now use
  `datetime.now(UTC)`.
- Dead parameters removed: `source_has_photo_table` (computed, passed, never
  read), `_serialize_value(key=...)`, and unused `request` on two NiceGUI
  page handlers where the framework injects it optionally.
- Mechanical line-length wrapping and one `startswith` tuple collapse.
- `# noqa: PLR0915` / `# noqa: PLR1702` on five long UI/migration
  functions, following the convention already used in jobs_page and
  settings_page, rather than refactoring during stabilization.

Full suite green (377 tests, `-m "not external"`).

Co-authored-by: Copilot App <[email protected]>

tests/services/test_v2_crud.py

@@ -61,15 +61,21 @@ async def test_people_service_handles_person_and_document_person_crud(default_se
 async def test_people_service_normalizes_and_rejects_duplicate_family_search_ids(default_session_factory):
     people_service = PeopleService(session_factory=default_session_factory)
 
-    created = await people_service.create_person(Person(given_names="Hig", last_name="Higgins", family_search_id=" g8t4-mdq "))
+    created = await people_service.create_person(
+        Person(given_names="Hig", last_name="Higgins", family_search_id=" g8t4-mdq ")
+    )
     assert created.family_search_id == "G8T4-MDQ"
 
     with pytest.raises(PeopleError) as duplicate:
-        await people_service.create_person(Person(given_names="Duplicate", last_name="Hig", family_search_id="G8T4-MDQ"))
+        await people_service.create_person(
+            Person(given_names="Duplicate", last_name="Hig", family_search_id="G8T4-MDQ")
+        )
     assert duplicate.value.category == ErrorCategory.CONFLICT
 
     with pytest.raises(PeopleError) as malformed:
-        await people_service.create_person(Person(given_names="Malformed", last_name="Person", family_search_id="not-an-id"))
+        await people_service.create_person(
+            Person(given_names="Malformed", last_name="Person", family_search_id="not-an-id")
+        )
     assert malformed.value.category == ErrorCategory.VALIDATION