feat: v0.5.16 - migrate to Responses API (#586)

* refactor: migrate from /v1/runs to /v1/responses streaming API

Replace EventSource-based polling with direct SSE streaming via the
/v1/responses endpoint across all server-side callers (chat-run-socket,
context-compressor, gateway-client, agent-clients). Messages are now
written to DB in real-time during streaming, eliminating post-run sync.
Frontend chat store adds tool_call_id tracking for deduplication.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* chore: bump version to 0.5.16 and add changelog

- Persist real API usage to usage table on response.completed
- Remove unused codex_reasoning_items field from message schema
- Fix unused variable warnings in chat-run-socket
- Bump version to 0.5.16
- Add changelog entries for 0.5.16 (8 locales)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

packages/server/src/services/hermes/session-sync.ts

@@ -107,7 +107,6 @@ async function syncProfileSessions(profile: string): Promise<{
             reasoning: msg.reasoning,
             reasoning_details: msg.reasoning_details,
             reasoning_content: msg.reasoning_content,
-            codex_reasoning_items: msg.codex_reasoning_items,
           })
         }