fix: resolve all linting errors, add tests, bump base image

Linting (ruff):
- cli.py: sort relative imports (I001)
- jobs.py: remove unused get_people import (F401), wrap long line (E501)
- executor.py: remove unused success variable (F841), wrap 4 long lines (E501)

Tests (24 passing):
- tests/test_config.py: config singleton defaults + env var overrides
- tests/test_upload_tracker.py: mark/filter/reset/summary logic
- tests/test_immich_api.py: filter_recent_assets date boundary cases
- tests/test_jobs.py: _resolve_strategy with LIMIT env var and fallbacks
- pyproject.toml: add [tool.pytest.ini_options] testpaths=["tests"] so
  pytest doesn't scan .venv in CI

Security:
- Dockerfile: bump CUDA base from 12.6.3 to 12.9.2 to pick up patched
  Ubuntu packages (fixes Dependabot low-severity alert)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

if_curator/jobs.py

@@ -11,7 +11,7 @@ from rich.table import Table
 from .config import Config
 from .diversity import select_diverse_assets
 from .embeddings import is_embedding_available, load_embedding_model
-from .immich_api import fetch_all_assets, filter_recent_assets, get_people
+from .immich_api import fetch_all_assets, filter_recent_assets
 from .logging import console
 from .upload_tracker import filter_already_uploaded
 
@@ -231,7 +231,10 @@ def auto_configure(people: list[dict]) -> list[dict]:
     if min_face_count > 0:
         valid_people = [p for p in valid_people if p.get("assetCount", 0) >= min_face_count]
         if valid_people:
-            rprint(f"  Filtered to {len(valid_people)} people with ≥{min_face_count} assets (MIN_FACE_COUNT={min_face_count})")
+            rprint(
+                f"  Filtered to {len(valid_people)} people with"
+                f" ≥{min_face_count} assets (MIN_FACE_COUNT={min_face_count})"
+            )
 
     jobs = []
     for person in valid_people: