fix(users): admin-gated /users routes accept api-key auth

Local `require_admin` in users.py depended on `get_current_user`, which
is OAuth2 JWT only. That made every admin-gated /users route (list, get,
patch update, bind-agent, etc.) reject api-key clients with 401 even when
the api-key resolves to an is_admin=True user.

Switch to `get_current_user_or_apikey` (the one in deps.py) so X-API-Key
and Bearer-as-apikey fallback both work. The admin gate itself still
reads User.is_admin — only the auth carrier broadens. Matches the auth
pattern schedule_type.py and other admin routes already use.

Surfaced when sherlock (agent-resource-director) tried `hf user list` for
the recruitment workflow Step 3 verify and got 401 "Could not validate
credentials" despite a valid provisioned api-key.

app/api/routers/users.py

@@ -39,7 +39,11 @@ def _user_response(user: models.User) -> dict:
     return data
 
 
-def require_admin(current_user: models.User = Depends(get_current_user)):
+def require_admin(current_user: models.User = Depends(get_current_user_or_apikey)):
+    # Accept either OAuth2 JWT or X-API-Key (incl. Bearer-as-apikey fallback)
+    # so CLI clients using their provisioned api-key can hit admin-gated user
+    # routes (list / get / update / patch). The admin gate still reads
+    # User.is_admin — only the auth carrier broadens.
     if not current_user.is_admin:
         raise HTTPException(status_code=403, detail="Admin required")
     return current_user