feat(generate): 图片持久化到本地 generation/ 目录，前端对接真实 API

后端:
- POST /api/v1/generate 接收 projectId，生成 taskId，将图片保存至 generation/{projectId}/{taskId}/
- 新增 GET /api/v1/tasks/:taskId 和 GET /api/v1/tasks/:taskId/assets 查询端点
- 添加 /generation 静态文件服务，前端可通过 URL 直接访问生成的图片
- PipelineInput 增加 ProjectID/TaskID 字段

前端:
- generate.ts 对接真实后端 API，移除 mock 模式
- 401 时不再强制登出跳转，改为抛错由调用方处理
- GeneratePage 加载工程风格，传递 projectId 和完整参数
- generation store 简化为同步 API 模式，移除 WebSocket mock
- ResultPage 使用 getTask/getAssets 按 taskId 查询结果

frontend/src/pages/GeneratePage.tsx

@@ -1,27 +1,35 @@
 import { useEffect } from 'react'
 import { useNavigate, useParams } from 'react-router-dom'
 import { useTaskStore } from '../stores/task'
+import { useProjectStore } from '../stores/project'
 import { useGenerationStore } from '../stores/generation'
 import { useToastStore } from '../stores/toast'
+import { extractTags } from '../api/prompt'
+import { mergeStyles } from '../utils/style'
+import type { GenerateRequest } from '../api/types'
 import GenerateForm from '../components/GenerateForm'
 import ProgressBar from '../components/ProgressBar'
 
 export default function GeneratePage() {
   const { projectId = 'proj-default' } = useParams()
   const navigate = useNavigate()
-  const { assetType, reset: resetTask } = useTaskStore()
   const addToast = useToastStore(s => s.addToast)
+
+  const taskStore = useTaskStore()
+  const { style: projectStyle, loadProject } = useProjectStore()
   const {
     status,
-    stage,
     progress,
-    retryCount,
-    rejectReason,
     taskId,
     submit,
     reset: resetGeneration,
   } = useGenerationStore()
 
+  // 加载工程风格
+  useEffect(() => {
+    loadProject(projectId)
+  }, [projectId, loadProject])
+
   // 组件卸载时重置生成状态
   useEffect(() => {
     return () => resetGeneration()
@@ -30,48 +38,57 @@ export default function GeneratePage() {
   // 失败时显示 toast
   useEffect(() => {
     if (status === 'failed') {
-      addToast({ type: 'error', message: '素材生成失败，请重试' })
+      const errText = useGenerationStore.getState().error || '未知错误'
+      addToast({ type: 'error', message: `素材生成失败：${errText}` })
     }
   }, [status, addToast])
 
-  // 完成后自动跳转
-  useEffect(() => {
-    if (status === 'completed' && taskId) {
-      const timer = setTimeout(() => {
-        navigate(`/projects/${projectId}/tasks/${taskId}`)
-      }, 1500)
-      return () => clearTimeout(timer)
-    }
-  }, [status, taskId, projectId, navigate])
-
   const handleSubmit = async (finalPrompt: string) => {
-    await submit(projectId, finalPrompt, assetType)
+    const { taskStyle, params, enableAI, optimizedPrompt } = taskStore
+    const mergedStyle = mergeStyles(projectStyle, taskStyle)
+    const tags = extractTags(mergedStyle)
+
+    const req: GenerateRequest = {
+      projectId,
+      prompt: enableAI && optimizedPrompt ? optimizedPrompt : finalPrompt,
+      assetType: taskStore.assetType,
+      tags,
+      projectStyle,
+      taskStyle,
+      resolution: params.resolution,
+      directions: params.frames?.directions,
+      framesPerDir: params.frames?.framesPerDirection,
+      format: params.format,
+    }
+
+    await submit(req)
+  }
+
+  const handleViewResult = () => {
+    if (taskId) navigate(`/projects/${projectId}/tasks/${taskId}`)
   }
 
   const handleReset = () => {
     resetGeneration()
-    resetTask()
+    taskStore.reset()
   }
 
   return (
     <div className="container page-enter" style={{ paddingTop: 24, paddingBottom: 40 }}>
       <h1 style={{ fontSize: 24, marginBottom: 32 }}>新建生成</h1>
 
-      {/* 生成表单 */}
       {status === 'idle' || status === 'submitting' ? (
         <GenerateForm onSubmit={handleSubmit} submitting={status === 'submitting'} />
       ) : (
         <div style={{ display: 'flex', flexDirection: 'column', gap: 24 }}>
-          {/* 进度条 */}
           <ProgressBar
-            stage={stage}
+            stage={null}
             progress={progress}
             status={status}
-            retryCount={retryCount}
-            rejectReason={rejectReason}
+            retryCount={0}
+            rejectReason={null}
           />
 
-          {/* 状态提示 */}
           {status === 'running' && (
             <p style={{ textAlign: 'center', color: 'var(--text-secondary)' }}>
               管线执行中，请稍候...
@@ -79,14 +96,26 @@ export default function GeneratePage() {
           )}
 
           {status === 'completed' && (
-            <p style={{ textAlign: 'center', color: 'var(--success)' }}>
-              ✓ 生成完成，正在跳转到结果页...
-            </p>
+            <div style={{ textAlign: 'center' }}>
+              <p style={{ color: 'var(--success)', marginBottom: 16 }}>
+                生成完成
+              </p>
+              <div style={{ display: 'flex', gap: 12, justifyContent: 'center' }}>
+                <button className="btn-primary" onClick={handleViewResult}>
+                  查看结果
+                </button>
+                <button className="btn-secondary" onClick={handleReset}>
+                  继续生成
+                </button>
+              </div>
+            </div>
           )}
 
           {status === 'failed' && (
             <div style={{ textAlign: 'center' }}>
-              <p style={{ color: 'var(--error)', marginBottom: 16 }}>生成失败</p>
+              <p style={{ color: 'var(--error)', marginBottom: 16 }}>
+                {useGenerationStore.getState().error || '生成失败'}
+              </p>
               <button className="btn-primary" onClick={handleReset}>
                 重新开始
               </button>