feat: expose all interactive CLI options via env vars

- config.py: wire BLUR_THRESHOLD, MIN_CONFIDENCE, MAX_AUTO_IMAGES,
  FACE_MARGIN, USE_FULL_RESOLUTION, ENABLE_FACE_ALIGNMENT to env vars
  (were hardcoded class defaults, inaccessible in AUTO_MODE)
- jobs.py: add LIMIT env var for custom image count in auto mode;
  overrides STRATEGY preset (mirrors interactive Custom Count option)
- compose.yml: document all env vars with inline comments grouped by
  concern — mode/strategy, people filtering, image quality, caching,
  tracker overrides, scheduling

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

if_curator/jobs.py

@@ -63,8 +63,14 @@ def _get_strategy_choice(has_embedding: bool, entity_type: str) -> tuple[int | s
 
 def _resolve_strategy(strategy: str, has_embedding: bool) -> tuple[int | str, str]:
     """Resolve env var strategy to (limit, selection_mode) without prompts."""
+    custom_limit = os.environ.get("LIMIT", "").strip()
+
     if not has_embedding:
-        return 30, "time"
+        limit = int(custom_limit) if custom_limit else 30
+        return limit, "time"
+
+    if custom_limit:
+        return int(custom_limit), "smart"
 
     strategy_map = {
         "auto": ("auto", "smart"),