Fix startup: add runpod to requirements, make import optional

- Add runpod>=1.6.0 to requirements.txt
- Remove higgsfield-client (not needed, SDK doesn't exist)
- Make runpod import optional in routes_video.py

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

requirements.txt

@@ -13,4 +13,4 @@ httpx>=0.26.0
 pyyaml>=6.0
 python-multipart>=0.0.6
 python-dotenv>=1.0.0
-higgsfield-client>=0.1.0
+runpod>=1.6.0

src/content_engine/api/routes_video.py

@@ -10,10 +10,17 @@ import time
 import uuid
 from pathlib import Path
 
-import runpod
 from fastapi import APIRouter, File, Form, HTTPException, UploadFile
 from pydantic import BaseModel
 
+# Optional RunPod import
+try:
+    import runpod
+    RUNPOD_AVAILABLE = True
+except ImportError:
+    runpod = None
+    RUNPOD_AVAILABLE = False
+
 logger = logging.getLogger(__name__)
 
 router = APIRouter(prefix="/api/video", tags=["video"])