### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

When using pass-through endpoints with `store_model_in_db: true`, CPU usage gradually climbs to 100% and stays there, even when idle. Profiling with `py-spy` shows that `remove_endpoint_routes` in `pass_through_endpoints.py` consumes **42.91 seconds of CPU** — nearly the entire `initialize_pass_through_endpoints` cycle.

**Root cause:**

LiteLLM reloads pass-through endpoints from the DB every ~30 seconds. The DB records have no `id` field, so `_register_pass_through_endpoint` generates a **new UUID** on every reload cycle (line 2154-2155):

```python if endpoint_data.get("id") is None: endpoint_data["id"] = str(uuid.uuid4()) ```

This new UUID becomes part of the route key (`{endpoint_id}:exact:{path}:{methods}`), which is inserted into `_registered_pass_through_routes`. During cleanup, the code iterates through all entries looking for matching `endpoint_id`:

```python # remove_endpoint_routes (line 2008-2027) keys_to_remove = [ key for key, value in _registered_pass_through_routes.items() if value["endpoint_id"] == endpoint_i…