Q71: rate limits seen on successful calls are recorded and park an exhausted provider

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/main/services/provider-tool-turn.ts

@@ -1,3 +1,4 @@
+import type { ProviderObservedRateLimitState } from "../../shared/provider-runtime-domain";
 /**
  * Shared contract for a single tool-use ("function calling") turn against any
  * provider backend. The agent loop maintains a normalized conversation
@@ -30,6 +31,8 @@ export interface AgentTurnResult {
   text: string;
   toolCalls: ToolCall[];
   rawResponseJson: string;
+  /** Rate-limit headers of the response, when the provider sent any. */
+  rateLimitState?: ProviderObservedRateLimitState | null;
 }
 
 /** Resolved per-request credential, already refreshed if it was an OAuth token. */