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/tools/test_export_import_migration.py

@@ -2,23 +2,21 @@ from __future__ import annotations
 
 from datetime import UTC
 from datetime import datetime
-from pathlib import Path
 from uuid import uuid4
 
 from sqlalchemy import create_engine
-from sqlalchemy import text
 from sqlalchemy import select
+from sqlalchemy import text
 from sqlmodel import SQLModel
 
+# Register table metadata.
+from transcription.db import models as _models  # noqa: F401
 from transcription.db.migration import MigrationPaths
 from transcription.db.migration import export_bundle
 from transcription.db.migration import import_bundle
 from transcription.db.migration import migrate_via_bundle
 from transcription.db.migration import sqlite_url_from_path
 
-# Register table metadata.
-from transcription.db import models as _models  # noqa: F401
-
 
 def test_export_import_migration_round_trips_db_and_uploads(tmp_path):
     source_db_path = tmp_path / "source.db"
@@ -173,7 +171,10 @@ def test_export_import_migration_backfills_legacy_portraits_and_homepage_images(
                 {"id": person_id},
             ).one()
             photos = connection.execute(
-                text('select person_id, path, is_primary from "photo" order by person_id is not null desc, created_at asc')
+                text(
+                    'select person_id, path, is_primary from "photo" '
+                    "order by person_id is not null desc, created_at asc"
+                )
             ).all()
         assert person_name[0] == "Legacy"
         assert person_name[1] == "Portrait"
@@ -291,7 +292,9 @@ def test_migration_backfills_legacy_media_when_photo_table_contains_stale_rows(t
     target_engine = create_engine(target_db_url)
     try:
         with target_engine.connect() as connection:
-            photos = connection.execute(text('select person_id, path from "photo" order by person_id is null, path')).all()
+            photos = connection.execute(
+                text('select person_id, path from "photo" order by person_id is null, path')
+            ).all()
         # stale row must not survive; legacy portrait + homepage should be backfilled
         assert len(photos) == 2
         assert any(row[0] is not None for row in photos)