Refactor codebase following Clean Code principles and add 229 tests

- Extract helpers to reduce function sizes (listing_tasks, app.py, query.py, listing_fetcher)
  - Replace nonlocal mutations with _PipelineState dataclass in listing_tasks
  - Fix bugs: isinstance→equality check in repository, verify_exp for OIDC tokens
  - Consolidate duplicate filter methods in listing_repository
  - Move hardcoded config to env vars with backward-compatible defaults
  - Simplify CLI decorator to auto-build QueryParameters
  - Add deprecation docstring to data_access.py
  - Test count: 158 → 387 (all passing)

crawler/services/listing_cache.py

@@ -4,12 +4,13 @@ import json
 import logging
 import os
 from typing import Generator
+from urllib.parse import urlparse, urlunparse
 
 import redis
 
 from models.listing import QueryParameters
 
-logger = logging.getLogger("uvicorn.error")
+logger = logging.getLogger(__name__)
 
 CACHE_PREFIX = "listings:geojson:"
 CACHE_TTL_SECONDS = 30 * 60  # 30 minutes
@@ -19,9 +20,9 @@ CACHE_DB = 2
 def _get_redis_client() -> redis.Redis:
     """Get Redis client using Celery broker URL but overriding to db=2."""
     broker_url = os.getenv("CELERY_BROKER_URL", "redis://localhost:6379/0")
-    # Replace the db number in the URL
-    base_url = broker_url.rsplit("/", 1)[0]
-    return redis.from_url(f"{base_url}/{CACHE_DB}", decode_responses=True)
+    parsed = urlparse(broker_url)
+    cache_url = urlunparse(parsed._replace(path=f"/{CACHE_DB}"))
+    return redis.from_url(cache_url, decode_responses=True)
 
 
 def make_cache_key(query_params: QueryParameters) -> str:
@@ -89,7 +90,10 @@ def invalidate_cache() -> None:
         while True:
             cursor, keys = client.scan(cursor, match=f"{CACHE_PREFIX}*", count=100)
             if keys:
-                client.delete(*keys)
+                pipeline = client.pipeline()
+                for key in keys:
+                    pipeline.delete(key)
+                pipeline.execute()
                 deleted += len(keys)
             if cursor == 0:
                 break