A09: Use static registry for CLI choices, check enabled at runtime

Bug: 'choices=configured_sources()' in argparse opened DB session at
import time, causing --help to fail when DB was unavailable.

Fix:
- Added STATIC_SOURCE_CHOICES list with known source keys
- argparse uses static choices — no DB required for --help
- fetch-community command now checks enabled status at runtime
- Disabled sources return error: 'source X is disabled or not configured'
- run_source still handles locked/cooling down state

Verification:
- CLI --help works without DB
- fetch-community --help shows all known sources
- Disabled sources are rejected at runtime with clear error
- 124/124 Python tests pass (1 skipped)

apps/api/app/cli.py

@@ -12,7 +12,16 @@ from .community_importer import stage_observations
 from .retention import RetentionPolicy, apply_retention
 from .storage import delete_screenshot
 from .catalog_audit import audit_catalog
-from .community_scheduler import configured_sources, run_source
+from .community_scheduler import run_source, configured_sources
+
+# Static registry for argparse choices — no DB required for --help
+STATIC_SOURCE_CHOICES = [
+    "rf4db",
+    "rf4stat-fishing",
+    "rf4stat-post",
+    "rf4map",
+    "rf4posts-spot",
+]
 
 
 def main() -> int:
@@ -26,7 +35,7 @@ def main() -> int:
     community.add_argument("--input", default="-", help="JSON array path or - for stdin")
     community.add_argument("--limit", type=int, default=500)
     fetch_community = sub.add_parser("fetch-community")
-    fetch_community.add_argument("source", choices=configured_sources())
+    fetch_community.add_argument("source", choices=STATIC_SOURCE_CHOICES)
     cleanup = sub.add_parser("cleanup-retention")
     cleanup.add_argument("--apply", action="store_true", help="apply changes; default is dry-run")
     sub.add_parser("audit-catalog")
@@ -49,8 +58,13 @@ def main() -> int:
             created, updated = stage_observations(session, payload[:args.limit])
             print(f"staged: created={created} updated={updated}")
         elif args.command == "fetch-community":
+            # A09: Verify source is enabled at runtime (not just in static choices)
+            enabled = configured_sources()
+            if args.source not in enabled:
+                print(f"source {args.source!r} is disabled or not configured", file=sys.stderr)
+                return 1
             started = run_source(args.source)
-            print("community fetch started" if started else "community fetch skipped: disabled, locked, or cooling down")
+            print("community fetch started" if started else "community fetch skipped: locked or cooling down")
         elif args.command == "cleanup-retention":
             policy = RetentionPolicy(
                 submission_days=settings.retention_submission_days,