fix: env var overrides for campaign settings (hf_token, ollama_host etc)

backend/app/routers/campaigns.py

@@ -1,6 +1,7 @@
 from fastapi import APIRouter, HTTPException
 
-from .. import database as db, config
+from .. import database as db
+from ..config import CAMPAIGN_SETTINGS, merge_campaign_settings_with_env
 
 router = APIRouter(prefix="/api/campaigns", tags=["campaigns"])
 
@@ -52,17 +53,14 @@ def get_campaign_settings(campaign_id: str):
     if not db.get_campaign(campaign_id):
         raise HTTPException(404, "Campaign not found")
     raw = db.get_campaign_settings(campaign_id)
-    # return defaults for any missing keys
-    merged = {**config.CAMPAIGN_SETTINGS, **raw}
-    return merged
+    return merge_campaign_settings_with_env(raw)
 
 
 @router.post("/{campaign_id}/settings")
 def update_campaign_settings(campaign_id: str, body: dict):
     if not db.get_campaign(campaign_id):
         raise HTTPException(404, "Campaign not found")
-    clean = {k: str(v) for k, v in body.items() if k in config.CAMPAIGN_SETTINGS}
+    clean = {k: str(v) for k, v in body.items() if k in CAMPAIGN_SETTINGS}
     db.update_campaign_settings(campaign_id, clean)
     raw = db.get_campaign_settings(campaign_id)
-    merged = {**config.CAMPAIGN_SETTINGS, **raw}
-    return merged
+    return merge_campaign_settings_with_env(raw)