refactor: Gitea 式目录改组，移除本分支 SPA 与杂项产物

将 model/service/handler/middleware 迁至 models/services/routers/api/modules/auth，并删除 frontend、embed_static、scripts 及误入库缓存/二进制。

Co-authored-by: Cursor <cursoragent@cursor.com>

routers/api/thumb.go

@@ -0,0 +1,32 @@
+package handler
+
+import (
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"git.iioio.com/freefire/jiang13-forum/service"
+)
+
+// ServeImageThumb 帖子图片缩略图（按需生成并缓存）
+// GET /media/thumb/posts/xxx.webp → 最长边 1280 的 WebP 预览
+func (h *Handlers) ServeImageThumb(c *gin.Context) {
+	rel := strings.TrimPrefix(c.Param("filepath"), "/")
+	uploadsRoot := filepath.Join(h.Cfg.DataDir, "uploads")
+	thumbPath, err := service.EnsureUploadThumb(uploadsRoot, rel)
+	if err != nil {
+		// 生成失败时回退原图，避免正文裂图
+		orig := filepath.Join(uploadsRoot, filepath.FromSlash(rel))
+		if st, e := os.Stat(orig); e == nil && !st.IsDir() {
+			c.Header("Cache-Control", "public, max-age=3600")
+			c.File(orig)
+			return
+		}
+		c.Status(http.StatusNotFound)
+		return
+	}
+	c.Header("Cache-Control", "public, max-age=604800, immutable")
+	c.File(thumbPath)
+}