feat(skill-evolution): expose model_name as per-user configurable field

前端恢复模型选择器，后端允许 model_name 写入 per-user skill_evolution.json。

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

offline-backend-20260512/backend/app/gateway/routers/skills.py

@@ -2329,14 +2329,15 @@ class CuratorConfigResponse(BaseModel):
 
 
 class CuratorConfigRequest(BaseModel):
-    """Payload for updating the three user-facing curator thresholds in skill_evolution.json.
+    """Payload for updating user-facing curator settings in skill_evolution.json.
 
-    All other settings (enabled, model, timeouts) are controlled via config.yaml.
+    All other settings (enabled, timeouts) are global-only and controlled via config.yaml.
     """
 
     interval_hours: int = Field(..., ge=1, description="Hours between curator runs.")
     stale_after_days: int = Field(..., ge=1, description="Days of inactivity before a skill is marked stale.")
     archive_after_days: int = Field(..., ge=1, description="Days of inactivity before a stale skill is archived.")
+    model_name: str | None = Field(default=None, description="Model for the curator LLM review; null = primary model.")
 
 
 class CuratorLogRecord(BaseModel):
@@ -2394,6 +2395,7 @@ async def update_curator_config(body: CuratorConfigRequest, request: Request) ->
                 "interval_hours": body.interval_hours,
                 "stale_after_days": body.stale_after_days,
                 "archive_after_days": body.archive_after_days,
+                "model_name": body.model_name,
             },
         })
         return _build_curator_config_response(load_skill_evolution_config_for_user(user_id))

offline-backend-20260512/backend/packages/harness/deerflow/config/skill_evolution_runtime.py

@@ -137,7 +137,7 @@ def resolve_user_path(user_id: str) -> Path:
 
 # Only these curator sub-fields may be overridden per user.
 # All other fields (enabled, model_name, timeouts, etc.) are global-only.
-_USER_ALLOWED_CURATOR_KEYS = {"interval_hours", "stale_after_days", "archive_after_days"}
+_USER_ALLOWED_CURATOR_KEYS = {"interval_hours", "stale_after_days", "archive_after_days", "model_name"}
 
 
 def load_user_overrides(user_id: str) -> dict[str, Any] | None: