Include usage_id in LLM log events to preserve per-usage_id folders

[enyst]

I'm OpenHands-GPT-5, proposing a focused fix to ensure LLM completion logs are routed to the correct client folders.

Summary

• The original PR streams LLM completion logs but the event does not include usage_id. On the client, RemoteConversation keeps a usage_id -> folder map, so missing usage_id forces a fallback to the first folder, breaking the intended per-usage_id directory layout.

What this PR changes

• Adds usage_id to LLMCompletionLogEvent
• In the agent server, captures llm.usage_id when setting the telemetry callback and includes it in the emitted event
• On the client, uses event.usage_id to pick the correct log_completions_folder, with a safe fallback for robustness

Rationale

• We have direct access to llm.usage_id in EventService where callbacks are registered, so including it in the event is simple and reliable
• Avoids guessing from model_name (which is ambiguous when multiple LLMs share the same model string)
• Preserves the user’s original intent to store logs per usage_id

Backward compatibility

• LLMCompletionLogEvent was introduced in the base PR; adding a field is backward-compatible within this change set and only affects the new streaming path

Implementation notes

• Server-side: closure capture of usage_id in _setup_llm_log_streaming via make_log_callback(usage_id) keeps Telemetry generic and unchanged
• Client-side: _create_llm_completion_log_callback now selects the folder by usage_id first, then falls back to the first configured directory if needed

Tests and quality

• Pre-commit hooks (ruff fmt/lint, pycodestyle, pyright) pass on changed files
• The change is minimal and focused; no unrelated edits

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@enyst Could you please take a look? This should address the concern about identifying the correct log directory per usage_id while keeping the streaming approach intact.

@enyst can click here to continue refining the PR

[github-actions]

Coverage Report •

File	Stmts	Miss	Cover	Missing
openhands-sdk/openhands/sdk/conversation/impl
remote_conversation.py	405	280	30%	50–62, 69–72, 92–97, 100–104, 107–111, 114–116, 118–121, 124–127, 130–131, 133–145, 148–153, 170–174, 176, 180, 182–183, 185–188, 190, 196, 198, 200–202, 204–206, 210, 212–215, 219, 224–225, 227, 230, 239–240, 243–244, 257–259, 262–263, 267, 269–270, 273, 276–278, 282, 284, 286–288, 291–293, 298–300, 302, 307, 312, 317–320, 323, 332, 340–343, 346, 351–354, 356, 361–362, 367–371, 376–380, 385–388, 391, 396–398, 402–403, 407, 411, 414, 459–464, 467–469, 471, 473–474, 486, 489, 491–493, 496, 499, 501, 504, 507–508, 511–512, 515–517, 520, 522, 524–526, 530, 532–533, 536, 539, 542, 548, 551, 553–554, 556, 560, 562–564, 569, 572–573, 576–577, 579, 581, 584, 586, 588, 591–593, 595–597, 599, 603, 608, 612, 618, 625–627, 630, 635–637, 645–646, 653, 655–659, 662–663, 672–673, 682, 690, 695–697, 699, 702, 704–705, 722, 729, 735–736, 745, 747–751, 753, 756–759
openhands-sdk/openhands/sdk/event
llm_completion_log.py	11	1	90%	36
TOTAL	6799	4309	36%