feat: add river-backed async task queue

apps/web/src/api.ts

@@ -521,6 +521,7 @@ export async function createChatTask(
 ): Promise<{ task: GatewayTask; next: Record<string, string> }> {
   return request<{ task: GatewayTask; next: Record<string, string> }>('/api/v1/chat/completions', {
     body: input,
+    headers: { 'X-Async': 'true' },
     method: 'POST',
     token,
   });
@@ -598,6 +599,7 @@ export async function createImageGenerationTask(
 ): Promise<{ task: GatewayTask; next: Record<string, string> }> {
   return request<{ task: GatewayTask; next: Record<string, string> }>('/api/v1/images/generations', {
     body: input,
+    headers: { 'X-Async': 'true' },
     method: 'POST',
     token,
   });
@@ -609,6 +611,7 @@ export async function createImageEditTask(
 ): Promise<{ task: GatewayTask; next: Record<string, string> }> {
   return request<{ task: GatewayTask; next: Record<string, string> }>('/api/v1/images/edits', {
     body: input,
+    headers: { 'X-Async': 'true' },
     method: 'POST',
     token,
   });
@@ -636,6 +639,7 @@ export async function createVideoGenerationTask(
 ): Promise<{ task: GatewayTask; next: Record<string, string> }> {
   return request<{ task: GatewayTask; next: Record<string, string> }>('/api/v1/videos/generations', {
     body: input,
+    headers: { 'X-Async': 'true' },
     method: 'POST',
     token,
   });
@@ -656,6 +660,33 @@ export async function getTask(token: string, taskId: string): Promise<GatewayTas
   return request<GatewayTask>(`/api/workspace/tasks/${taskId}`, { token });
 }
 
+export async function pollTaskUntilSettled(
+  token: string,
+  task: GatewayTask,
+  options: { intervalMs?: number; maxAttempts?: number | null; onUpdate?: (task: GatewayTask) => void } = {},
+): Promise<GatewayTask> {
+  let detail = task;
+  const intervalMs = options.intervalMs ?? 1200;
+  const maxAttempts = options.maxAttempts ?? Number.POSITIVE_INFINITY;
+  for (let attempt = 0; attempt < maxAttempts; attempt += 1) {
+    if (!taskIsPending(detail.status)) return detail;
+    try {
+      detail = await getTask(token, detail.id);
+      options.onUpdate?.(detail);
+      if (!taskIsPending(detail.status)) return detail;
+    } catch {
+      // Backend restarts or short network gaps should not turn a durable task into a failed UI run.
+      // Only an explicit terminal task status from the task detail endpoint settles the run.
+    }
+    await delay(intervalMs);
+  }
+  return detail;
+}
+
+export function taskIsPending(status: string) {
+  return status === 'queued' || status === 'running' || status === 'submitting';
+}
+
 export async function listTasks(token: string, query: WorkspaceTaskQuery): Promise<ListResponse<GatewayTask>> {
   const search = new URLSearchParams({
     page: String(query.page),
@@ -707,9 +738,9 @@ export async function getNetworkProxyConfig(token: string): Promise<GatewayNetwo
 
 async function request<T>(
   path: string,
-  options: { token?: string; auth?: boolean; method?: string; body?: unknown } = {},
+  options: { token?: string; auth?: boolean; method?: string; body?: unknown; headers?: Record<string, string> } = {},
 ): Promise<T> {
-  const headers: Record<string, string> = {};
+  const headers: Record<string, string> = { ...(options.headers ?? {}) };
   if (options.auth !== false && options.token) {
     headers.Authorization = `Bearer ${options.token}`;
   }
@@ -731,6 +762,10 @@ async function request<T>(
   return response.json() as Promise<T>;
 }
 
+function delay(ms: number) {
+  return new Promise((resolve) => window.setTimeout(resolve, ms));
+}
+
 function parseErrorMessage(body: string) {
   return formatGatewayErrorDetails(parseErrorDetails(body));
 }