Fix handler return types: return file path lists not dicts

job_server.py expects process() to return a list of file paths for
MinIO upload. The 499-Q and discontinuance handlers were returning
dicts like {'status':'admin_review'} which caused the job_server to
iterate dict keys as file paths -> 'File not found: status'.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/workers/services/form_499a_discontinuance.py

@@ -200,7 +200,8 @@ class Form499ADiscontinuanceHandler(BaseServiceHandler):
             filer_id=filer_id,
         )
 
-        return {"status": "submitted_for_processing", "letter_generated": bool(letter_path)}
+        # Return list of file paths for MinIO upload (letter already uploaded above)
+        return [letter_path] if letter_path else []
 
     def _send_confirmation(
         self, to: str, entity_name: str, order_number: str, filer_id: str,

scripts/workers/services/form_499q.py

@@ -48,7 +48,7 @@ class Form499QHandler(BaseServiceHandler):
 
         if not intake_data.get("intake_completed"):
             logger.info("Form499QHandler: %s intake not completed — waiting", order_number)
-            return None
+            return []
 
         quarter = intake_data.get("quarter", "?")
         revenue = intake_data.get("revenue", {})
@@ -92,7 +92,7 @@ class Form499QHandler(BaseServiceHandler):
                 quarter=quarter,
                 due_date=intake_data.get("due_date", ""),
             )
-            return {"status": "admin_review"}
+            return []  # no files to upload — admin will file manually
 
         # ── USAC E-File submission via Playwright ──────────────────────
         work_dir = tempfile.mkdtemp(prefix=f"499q_{order_number}_")
@@ -154,7 +154,7 @@ class Form499QHandler(BaseServiceHandler):
                 due_date=intake_data.get("due_date", ""),
             )
 
-        return {"status": "filed" if confirmation_number else "pending_manual", "confirmation": confirmation_number}
+        return []  # confirmation PDF already uploaded to MinIO in _submit_to_usac
 
     async def _submit_to_usac(
         self, order_number: str, entity: dict, intake_data: dict,