fix(agent): raise max iterations default from 10 to 200

The low default caused the agent to stop mid-task prematurely.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/backends/native/agent.ts

@@ -63,7 +63,7 @@ export class NativeAgent {
     this.session = config.session;
     this.toolRegistry = config.toolRegistry;
     this.toolExecutor = config.toolExecutor;
-    this.maxIterations = config.maxIterations ?? 10;
+    this.maxIterations = config.maxIterations ?? 200;
     this.onToolUse = config.onToolUse;
     this._toolPolicyContext = config.toolPolicyContext;
     this._attachmentCollector = config.attachmentCollector;