fix: consume [DONE] token after error events to prevent forced finalizer append
**Problem:**
Stream finalizer was frequently logging warning and appending forced [DONE]:
```
[Stream Finalizer] Appending forced [DONE] for run=run-xxx (saw_error=True,
saw_done=False, final_stop_reason=llm_api_error)
```
This happened on every error, even though streaming_service.py already yields
[DONE] after all error events.
**Root Cause:**
Line 266: `is_done = saw_done or saw_error` caused loop to break immediately
after seeing error event, BEFORE consuming the [DONE] chunk that follows:
```python
is_done = saw_done or saw_error
await writer.write_chunk(...)
if is_done: # Breaks on error!
break
```
Sequence:
1. streaming_service.py yields: `event: error\ndata: {...}\n\n`
2. Redis reader sees error → sets `saw_error=True`
3. Sets `is_done=True` and breaks
4. Never reads next chunk: `data: [DONE]\n\n`
5. Finalizer runs → `saw_done=False` → appends forced [DONE]
**Fix:**
1. Only break when `saw_done=True` (not `saw_error`) → allows consuming [DONE]
2. Only run finalizer when `saw_done=False` → reduces log noise
**Result:**
- [DONE] now consumed naturally from streaming_service.py error handlers
- Finalizer warning only appears when truly needed (fallback cases)
- Cleaner production logs
👾 Generated with [Letta Code](https://letta.com)
Co-authored-by: Letta <noreply@letta.com>
2a2e777807