## Summary
Wraps every caller-supplied identifier (thread_id, assistant_id, run_id,
cron_id, checkpoint_id, namespace) interpolated into request URL paths
with `urllib.parse.quote(safe="")` via a new `_quote_path_param` helper.
All-dot strings are encoded as `%2E` triplets so they aren't collapsed
by httpx's client-side path normalization. Helper raises `TypeError` for
None/bytes inputs.
## Test plan
- [x] `make format` / `make lint` / `make test` from `libs/sdk-py`
