feat: 首页展示最近生成的素材画廊

- 后端新增 GET /api/v1/assets 接口，返回已完成任务的素材列表（按创建时间倒序）
- 前端新增 AssetGallery 组件，网格展示素材缩略图、类型标签和提示词
- HomePage 中工程列表上方展示最近生成素材

backend/cmd/main.go

@@ -78,6 +78,7 @@ func main() {
 		v1Auth.POST("/generate", handler.Generate)               // 素材生成管线
 		v1Auth.GET("/tasks/:taskId", handler.GetTask)            // 查询任务
 		v1Auth.GET("/tasks/:taskId/assets", handler.GetAssets)   // 查询任务素材
+			v1Auth.GET("/assets", handler.GetRecentAssets)           // 首页最近素材
 		// 图片编辑
 		v1Auth.POST("/images/edit", handler.EditImage)           // 图片编辑
 	}

backend/internal/handler/generate.go

@@ -306,6 +306,58 @@ func getTaskDBID(ctx context.Context, taskID string) uint {
 	return task.ID
 }
 
+// RecentAssetItem 首页素材展示项。
+type RecentAssetItem struct {
+	Key       string `json:"key"`
+	URL       string `json:"url"`
+	Format    string `json:"format"`
+	Prompt    string `json:"prompt"`
+	AssetType string `json:"assetType"`
+	TaskID    string `json:"taskId"`
+	CreatedAt string `json:"createdAt"`
+}
+
+// GetRecentAssets 获取最近生成的素材列表（已完成任务的全部素材）。
+func GetRecentAssets(c *gin.Context) {
+	limit := 20
+
+	var dbRows []struct {
+		Key       string
+		URL       string
+		Format    string
+		Prompt    string
+		AssetType string
+		TaskID    string
+		ProjectID uint
+		CreatedAt string
+	}
+
+	db.GetDB().WithContext(c.Request.Context()).
+		Raw(`SELECT a.key, a.url, a.format, t.prompt, t.asset_type as asset_type,
+			t.external_id as task_id, t.project_id, t.created_at as created_at
+			FROM assets a
+			INNER JOIN tasks t ON a.task_id = t.id
+			WHERE t.status = 'completed'
+			ORDER BY a.created_at DESC
+			LIMIT ?`, limit).
+		Scan(&dbRows)
+
+	result := make([]RecentAssetItem, len(dbRows))
+	for i, r := range dbRows {
+		result[i] = RecentAssetItem{
+			Key:       r.Key,
+			URL:       storageSvc.GetSignedURL(r.Key),
+			Format:    r.Format,
+			Prompt:    r.Prompt,
+			AssetType: r.AssetType,
+			TaskID:    r.TaskID,
+			CreatedAt: r.CreatedAt,
+		}
+	}
+
+	c.JSON(http.StatusOK, model.OK(result))
+}
+
 // toTaskResponse 转换任务响应格式。
 func toTaskResponse(task *model.Task) model.TaskResponse {
 	return model.TaskResponse{

frontend/src/api/generate.ts

@@ -1,4 +1,9 @@
 import { post, get } from './client'
+import type { RecentAssetItem } from './types'
+
+export async function getRecentAssets(): Promise<RecentAssetItem[]> {
+  return get<RecentAssetItem[]>('/api/v1/assets')
+}
 import type {
   Asset,
   AssetsResponse,

frontend/src/api/types.ts

@@ -98,6 +98,17 @@ export interface Asset {
   index: number
 }
 
+// 首页最近素材
+export interface RecentAssetItem {
+  key: string
+  url: string
+  format: string
+  prompt: string
+  assetType: string
+  taskId: string
+  createdAt: string
+}
+
 // 生成请求 — 对应 POST /api/v1/generate
 export interface GenerateRequest {
   projectId: string

frontend/src/components/AssetGallery.tsx

@@ -0,0 +1,100 @@
+import { useEffect, useState } from 'react'
+import { getRecentAssets } from '../api/generate'
+import type { RecentAssetItem } from '../api/types'
+
+const ASSET_TYPE_LABELS: Record<string, string> = {
+  sprite: '精灵',
+  background: '背景',
+  ui: 'UI',
+  animation: '动画',
+}
+
+export default function AssetGallery() {
+  const [assets, setAssets] = useState<RecentAssetItem[]>([])
+  const [loading, setLoading] = useState(true)
+
+  useEffect(() => {
+    getRecentAssets()
+      .then(setAssets)
+      .catch(() => {})
+      .finally(() => setLoading(false))
+  }, [])
+
+  if (loading) return null
+
+  if (assets.length === 0) return null
+
+  return (
+    <section style={{ marginBottom: 32 }}>
+      <h2 style={{ fontSize: 18, marginBottom: 16 }}>最近生成</h2>
+      <div
+        style={{
+          display: 'grid',
+          gridTemplateColumns: 'repeat(auto-fill, minmax(180px, 1fr))',
+          gap: 12,
+        }}
+      >
+        {assets.map((item, i) => (
+          <div
+            key={`${item.taskId}-${i}`}
+            className="card"
+            style={{ padding: 8, cursor: 'pointer' }}
+            onClick={() => {
+              // navigate to result page — need projectId for URL
+              // For now just open the image
+            }}
+          >
+            <div
+              style={{
+                width: '100%',
+                aspectRatio: '1',
+                overflow: 'hidden',
+                borderRadius: 'var(--radius)',
+                background: 'var(--bg-input)',
+                display: 'flex',
+                alignItems: 'center',
+                justifyContent: 'center',
+              }}
+            >
+              <img
+                src={item.url}
+                alt={item.prompt}
+                loading="lazy"
+                style={{
+                  maxWidth: '100%',
+                  maxHeight: '100%',
+                  objectFit: 'contain',
+                }}
+              />
+            </div>
+            <div style={{ marginTop: 6 }}>
+              <span
+                style={{
+                  fontSize: 11,
+                  padding: '1px 6px',
+                  borderRadius: 999,
+                  background: 'var(--accent-dim)',
+                  color: 'var(--accent)',
+                }}
+              >
+                {ASSET_TYPE_LABELS[item.assetType] || item.assetType}
+              </span>
+            </div>
+            <p
+              style={{
+                fontSize: 12,
+                color: 'var(--text-secondary)',
+                marginTop: 4,
+                overflow: 'hidden',
+                textOverflow: 'ellipsis',
+                whiteSpace: 'nowrap',
+              }}
+            >
+              {item.prompt}
+            </p>
+          </div>
+        ))}
+      </div>
+    </section>
+  )
+}

frontend/src/pages/HomePage.tsx

@@ -2,6 +2,7 @@ import { useEffect, useState } from 'react'
 import { useProjectListStore } from '../stores/projectList'
 import { useToastStore } from '../stores/toast'
 import ProjectCard from '../components/ProjectCard'
+import AssetGallery from '../components/AssetGallery'
 import CreateProjectModal from '../components/CreateProjectModal'
 import EmptyState from '../components/EmptyState'
 import Skeleton from '../components/Skeleton'
@@ -39,6 +40,8 @@ export default function HomePage() {
 
   return (
     <div className="container page-enter" style={{ paddingTop: 32, paddingBottom: 32 }}>
+      <AssetGallery />
+
       <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginBottom: 24 }}>
         <h1 style={{ fontSize: 22 }}>我的工程</h1>
         <button className="btn-primary" onClick={() => setModalOpen(true)}>