story-219: add Always Allow button to web UI permission dialog

Cherry-pick from feature branch — code was never squash-merged
despite story being accepted (bug 226).

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

frontend/src/api/client.ts

@@ -11,6 +11,7 @@ export type WsRequest =
 			type: "permission_response";
 			request_id: string;
 			approved: boolean;
+			always_allow: boolean;
 	  }
 	| { type: "ping" };
 
@@ -469,8 +470,17 @@ export class ChatWebSocket {
 		this.send({ type: "cancel" });
 	}
 
-	sendPermissionResponse(requestId: string, approved: boolean) {
-		this.send({ type: "permission_response", request_id: requestId, approved });
+	sendPermissionResponse(
+		requestId: string,
+		approved: boolean,
+		alwaysAllow = false,
+	) {
+		this.send({
+			type: "permission_response",
+			request_id: requestId,
+			approved,
+			always_allow: alwaysAllow,
+		});
 	}
 
 	close() {