fix(webui): move mutations to authenticated websocket requests

webui/src/lib/nanobot-client.ts

@@ -108,6 +108,16 @@ interface PendingRequest<T> {
   timer: ReturnType<typeof setTimeout>;
 }
 
+export class WebUIMutationError extends Error {
+  status: number;
+
+  constructor(status: number, message: string) {
+    super(message);
+    this.status = status;
+    this.name = "WebUIMutationError";
+  }
+}
+
 interface PendingChatRequest extends PendingRequest<string> {
   temporary: boolean;
 }
@@ -203,6 +213,7 @@ export class NanobotClient {
   private pendingNewChat: PendingChatRequest | null = null;
   private pendingTranscriptions = new Map<string, PendingRequest<string>>();
   private pendingSystemCommands = new Map<string, PendingRequest<void>>();
+  private pendingWebUIRequests = new Map<string, PendingRequest<unknown>>();
   // Frames queued while the socket is not yet OPEN
   private sendQueue: Outbound[] = [];
   private reconnectAttempts = 0;
@@ -807,6 +818,60 @@ export class NanobotClient {
     });
   }
 
+  /**
+   * Send one non-replayable WebUI mutation over the authenticated socket.
+   * A client-side timeout only abandons the reply; the server may finish work
+   * that already started, so timed-out requests are never retried automatically.
+   */
+  requestMutation<T>(
+    action: string,
+    payload: Record<string, unknown> = {},
+    timeoutMs: number = 20_000,
+  ): Promise<T> {
+    const socket = this.socket;
+    if (!socket || socket.readyState !== WS_OPEN) {
+      return Promise.reject(
+        new WebUIMutationError(503, "WebUI connection is not open"),
+      );
+    }
+    const requestId = crypto.randomUUID();
+    const frame: Outbound = {
+      type: "webui_request",
+      request_id: requestId,
+      action,
+      payload,
+    };
+    if (!this.frameFitsTransport(frame)) {
+      return Promise.reject(
+        new WebUIMutationError(413, "WebUI mutation payload is too large"),
+      );
+    }
+
+    return new Promise<T>((resolve, reject) => {
+      const timer = setTimeout(() => {
+        this.pendingWebUIRequests.delete(requestId);
+        reject(
+          new WebUIMutationError(
+            504,
+            `WebUI request timed out after ${timeoutMs}ms`,
+          ),
+        );
+      }, timeoutMs);
+      this.pendingWebUIRequests.set(requestId, {
+        resolve: (value) => resolve(value as T),
+        reject,
+        timer,
+      });
+      try {
+        socket.send(JSON.stringify(frame));
+      } catch {
+        clearTimeout(timer);
+        this.pendingWebUIRequests.delete(requestId);
+        reject(new WebUIMutationError(503, "Could not send WebUI request"));
+      }
+    });
+  }
+
   /** Ask the server to create a non-destructive fork before a user-message index. */
   forkChat(
     sourceChatId: string,
@@ -914,8 +979,8 @@ export class NanobotClient {
     });
   }
 
-  setSidebarState(state: SidebarStatePayload): void {
-    this.queueSend({ type: "set_sidebar_state", state });
+  setSidebarState(state: SidebarStatePayload): Promise<SidebarStatePayload> {
+    return this.requestMutation<SidebarStatePayload>("sidebar.update", { state });
   }
 
   // -- internals ---------------------------------------------------------
@@ -965,6 +1030,23 @@ export class NanobotClient {
       console.log("[nanobot ws inbound]", summarizeInboundWsPayload(parsed));
     }
 
+    if (parsed.event === "webui_response") {
+      const pending = this.pendingWebUIRequests.get(parsed.request_id);
+      if (!pending) return;
+      clearTimeout(pending.timer);
+      this.pendingWebUIRequests.delete(parsed.request_id);
+      if (parsed.ok) {
+        pending.resolve(parsed.result);
+      } else {
+        const status = Number.isFinite(parsed.error?.status)
+          ? parsed.error.status
+          : 500;
+        const message = parsed.error?.message || "WebUI mutation failed";
+        pending.reject(new WebUIMutationError(status, message));
+      }
+      return;
+    }
+
     if (parsed.event === "error" && !parsed.turn_id) {
       const fallback = this.legacyRejectionTarget(parsed);
       if (fallback) {
@@ -1151,6 +1233,13 @@ export class NanobotClient {
       this.pendingNewChat = null;
     }
     this.rejectAllTranscriptions("socket closed");
+    for (const pending of this.pendingWebUIRequests.values()) {
+      clearTimeout(pending.timer);
+      pending.reject(
+        new WebUIMutationError(503, "Socket closed before WebUI response"),
+      );
+    }
+    this.pendingWebUIRequests.clear();
     for (const pending of this.pendingSystemCommands.values()) {
       clearTimeout(pending.timer);
       pending.reject(new Error("socket closed"));