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/db/hermes/sessions-db.ts

@@ -53,7 +53,6 @@ export interface HermesMessageRow {
   finish_reason: string | null
   reasoning: string | null
   reasoning_details?: string | null
-  codex_reasoning_items?: string | null
   reasoning_content?: string | null
 }
 
@@ -350,7 +349,6 @@ function mapMessageRow(row: Record<string, unknown>): HermesMessageRow {
     finish_reason: normalizeNullableString(row.finish_reason),
     reasoning,
     reasoning_details: normalizeNullableString(row.reasoning_details),
-    codex_reasoning_items: normalizeNullableString(row.codex_reasoning_items),
     reasoning_content: normalizeNullableString(row.reasoning_content),
   }
 }