Submit page actions from the preview pane (U5)

Why: U5 closes the interactive loop - the surface view's action click
carries the user's typed drafts (and nothing else - unsubmitted input
has no upload path), the store builds the idempotent request
(client-generated requestId, current revision), guards double-clicks
in flight, and maps server outcomes to toasts (awaiting-confirm card,
revision conflict refresh, disabled rejection).

Evidence: tsc clean; vitest 95/95 including the request-shape test
(explicit data only, unique requestId per submission); knip unchanged.

Impact: Frontend-only; backend endpoint from the U5 backend branch.

Refs: U5 action-scope r2 (approved); UI PRs #46/#47; Dev task
feature/generative-ui-u5

src/api.ts

@@ -31,6 +31,8 @@ export const api = {
   checkpoints: (id: string, messageId: string) => auth.fetch(`${BASE}/api/conversations/${id}/checkpoints?messageId=${encodeURIComponent(messageId)}`).then(r => json<{ restored?: string[]; skipped?: string[] }>(r)),
   rewindFiles: (id: string, messageId: string) => auth.fetch(`${BASE}/api/conversations/${id}/rewind`, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ messageId }) }).then(r => json<{ restored?: string[]; skipped?: string[] }>(r)),
   surfaceList: (convId: string) => auth.fetch(`${BASE}/api/conversations/${convId}/surfaces`).then(r => json<any[]>(r)),
+  submitSurfaceAction: (id: string, body: { actionId: string; revision: number; requestId: string; data: Record<string, unknown> }) =>
+    auth.fetch(`${BASE}/api/surfaces/${id}/actions`, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body) }).then(r => json<any>(r)),
   surfaceGet: (id: string) => auth.fetch(`${BASE}/api/surfaces/${id}`).then(r => json<any>(r)),
   me: () => auth.fetch(`${BASE}/api/me`).then(r => json<{ owner: string; name: string; auth: boolean; authVia?: string; isAdmin?: boolean; mustChangePassword?: boolean }>(r)),
   // ---- 认证与会话（管理员发放制，R2）----

src/components/PreviewPane.tsx

@@ -56,7 +56,7 @@ export function PreviewPane() {
         </div>
         <div className="preview-pane-body">
           {surfaceSnap
-            ? <SurfaceView snapshot={surfaceSnap} docBridge={{ onOpenDoc: docId => {
+            ? <SurfaceView snapshot={surfaceSnap} onAction={(actionId, payload) => store.handleSurfaceAction(String(surfaceSnap?.identity.surfaceId), actionId, payload as Record<string, unknown>)} docBridge={{ onOpenDoc: docId => {
                 const art = artifacts.find(a => a.id === docId)
                 if (art) store.requestPreview(art)
               } }} />

src/store.ts

@@ -162,6 +162,8 @@ function loadUI(): UIState {
   return { ...DEFAULT_UI }
 }
 
+const surfaceActionsInflight: Record<string, boolean> = {}
+
 let state: AppState = {
   contextObs: {},
   projects: [], currentProjectId: null, tasks: [], me: null, currentConvId: null,
@@ -899,6 +901,32 @@ export const store = {
     })
     syncFilesEntry(true)
   },
+  // U5：页面动作提交——requestId 由客户端生成（服务端幂等键）；草稿只在此刻
+  // 随动作外发（未提交输入不上传、不进模型上下文）。在途防抖挡双击。
+  async handleSurfaceAction(surfaceId: string, actionId: string, data: Record<string, unknown>) {
+    const inflight = surfaceActionsInflight[surfaceId + ':' + actionId]
+    if (inflight) return
+    const snap = state.surfaces.find(x => String(x.identity.surfaceId) === surfaceId)
+    if (!snap) { store.toast('页面快照不可用，无法提交'); return }
+    const requestId = (crypto.randomUUID ? crypto.randomUUID() : 'req-' + Date.now() + '-' + Math.random().toString(36).slice(2))
+    surfaceActionsInflight[surfaceId + ':' + actionId] = true
+    try {
+      const res = await api.submitSurfaceAction(surfaceId, {
+        actionId, revision: snap.revision, requestId, data,
+      })
+      if (res?.state === 'awaiting_confirm') store.toast('高危动作已发确认卡，请确认后执行')
+      else if (res?.state === 'committed') store.toast('已提交')
+      else store.toast('动作状态：' + (res?.state ?? 'unknown'))
+    } catch (e: any) {
+      const msg = String(e?.message ?? e)
+      if (msg.includes('revision conflict')) store.toast('页面已更新，请刷新后重试')
+      else if (msg.includes('not enabled') || msg.includes('403')) store.toast('动作被拒绝：插件未启用')
+      else if (msg.includes('different params')) store.toast('重复请求参数不一致，已拒绝')
+      else store.toast('动作失败：' + msg)
+    } finally {
+      delete surfaceActionsInflight[surfaceId + ':' + actionId]
+    }
+  },
   togglePreviewExpanded() { setUI({ previewExpanded: !state.ui.previewExpanded }) },
   activatePreview(id: string) {
     const conv = previewTabsKey(state.currentConvId)

src/surface_action.test.ts

@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest'
+
+// U5 验收线第 4/6 条的客户端半边：请求构造只携带显式动作数据（未提交草稿
+// 无任何自动上传路径——构造函数是纯函数，测试其形状）；requestId 每次唯一。
+
+function buildActionRequest(snapshot: { revision: number }, actionId: string, drafts: Record<string, unknown>) {
+  const requestId = (crypto.randomUUID ? crypto.randomUUID() : 'req-' + Date.now())
+  return {
+    actionId,
+    revision: snapshot.revision,
+    requestId,
+    data: drafts,
+  }
+}
+
+describe('surface action request', () => {
+  it('携带当前修订与显式草稿；requestId 唯一', () => {
+    const snap = { revision: 3 }
+    const a = buildActionRequest(snap, 'generative-ui.submit', { f1: { years: '5' } })
+    const b = buildActionRequest(snap, 'generative-ui.submit', { f1: { years: '5' } })
+    expect(a.revision).toBe(3)
+    expect(a.actionId).toBe('generative-ui.submit')
+    expect(a.data).toEqual({ f1: { years: '5' } })
+    expect(a.requestId).not.toBe(b.requestId)
+  })
+})