feat(storage): implement user-group level file management dashboard and APIs

- Expose user-scoped CRUD APIs under `/api/v1/upload` (my files query, stats, rename, delete)
- Update backend handlers and routers with ownership validation checks
- Create a dedicated frontend personal file manager card-list and upload button under `/files`
- Add comprehensive backend test coverage and update API docs

frontend/components/common/user/files.tsx

@@ -0,0 +1,31 @@
+"use client"
+
+import * as React from "react"
+import {motion} from "motion/react"
+
+import {UserFileManager} from "./file-manager"
+
+export function UserFilesMain() {
+  return (
+    <motion.div
+      initial={{ opacity: 0, y: 15 }}
+      animate={{ opacity: 1, y: 0 }}
+      transition={{ duration: 0.35, ease: "easeOut" }}
+      className="flex w-full flex-col gap-6 py-6"
+    >
+      {/* 顶部标题区 */}
+      <div className="flex flex-col md:flex-row md:items-center justify-between gap-4 border-b pb-5">
+        <div>
+          <h1 className="text-xl font-bold tracking-tight bg-gradient-to-r from-foreground via-foreground/90 to-muted-foreground bg-clip-text text-transparent">
+            我的文件
+          </h1>
+          <p className="text-sm text-muted-foreground">
+            管理您上传的个人文件，支持上传、下载、搜索与删除操作
+          </p>
+        </div>
+      </div>
+
+      <UserFileManager />
+    </motion.div>
+  )
+}