fix: abort model retries immediately on user cancellation

src/backends/native/agent.ts

@@ -100,6 +100,9 @@ export class NativeAgent {
 
   async process(userMessage: string, attachments?: Attachment[]): Promise<string> {
     this._cancelRequested = false;
+    if ('clearAbort' in this.modelClient && typeof this.modelClient.clearAbort === 'function') {
+      this.modelClient.clearAbort();
+    }
     this._runInProgress = true;
 
     // Detect and strip !!think prefix for per-message thinking mode
@@ -541,6 +544,9 @@ export class NativeAgent {
   cancel(): void {
     if (this._runInProgress) {
       this._cancelRequested = true;
+      if ('requestAbort' in this.modelClient && typeof this.modelClient.requestAbort === 'function') {
+        this.modelClient.requestAbort();
+      }
     }
   }