feat(admin): 添加APK管理功能

实现APK文件的上传、下载和列表功能
- 新增APKInfo数据结构
- 添加/admin/apk/upload、/admin/apk/download和/admin/apk/list路由
- 实现APK存储服务方法
- 添加相关测试用例

internal/handlers/handlers.go

@@ -212,6 +212,78 @@ func (h *Handler) AdminReleases(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]any{"releases": releases})
 }
 
+func (h *Handler) AdminUploadAPK(w http.ResponseWriter, r *http.Request) {
+	if !h.authorizeAdmin(w, r) {
+		return
+	}
+	if r.Method != http.MethodPost {
+		writeJSON(w, http.StatusMethodNotAllowed, map[string]any{"error": "Expected POST."})
+		return
+	}
+	runtimeVersion := r.URL.Query().Get("runtimeVersion")
+	if runtimeVersion == "" {
+		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "runtimeVersion is required"})
+		return
+	}
+	contentType := r.Header.Get("Content-Type")
+	if !strings.HasPrefix(contentType, "application/vnd.android.package-archive") &&
+		!strings.HasPrefix(contentType, "application/octet-stream") {
+		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "Content-Type must be application/vnd.android.package-archive or application/octet-stream"})
+		return
+	}
+	maxSize := int64(500 * 1024 * 1024)
+	r.Body = http.MaxBytesReader(w, r.Body, maxSize)
+	path, err := h.svc.SaveAPK(runtimeVersion, r.Body)
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"runtimeVersion": runtimeVersion,
+		"path":           path,
+		"message":        "APK uploaded successfully",
+	})
+}
+
+func (h *Handler) AdminDownloadAPK(w http.ResponseWriter, r *http.Request) {
+	if !h.authorizeAdmin(w, r) {
+		return
+	}
+	if r.Method != http.MethodGet {
+		writeJSON(w, http.StatusMethodNotAllowed, map[string]any{"error": "Expected GET."})
+		return
+	}
+	runtimeVersion := r.URL.Query().Get("runtimeVersion")
+	if runtimeVersion == "" {
+		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "runtimeVersion is required"})
+		return
+	}
+	apkPath, err := h.svc.GetAPKPath(runtimeVersion)
+	if err != nil {
+		writeJSON(w, http.StatusNotFound, map[string]any{"error": fmt.Sprintf("APK for runtimeVersion %s not found", runtimeVersion)})
+		return
+	}
+	w.Header().Set("Content-Type", "application/vnd.android.package-archive")
+	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=%s.apk", runtimeVersion))
+	http.ServeFile(w, r, apkPath)
+}
+
+func (h *Handler) AdminListAPKs(w http.ResponseWriter, r *http.Request) {
+	if !h.authorizeAdmin(w, r) {
+		return
+	}
+	if r.Method != http.MethodGet {
+		writeJSON(w, http.StatusMethodNotAllowed, map[string]any{"error": "Expected GET."})
+		return
+	}
+	apks, err := h.svc.ListAPKs()
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]any{"error": err.Error()})
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"apks": apks})
+}
+
 func (h *Handler) authorizeAdmin(w http.ResponseWriter, r *http.Request) bool {
 	if h.adminToken == "" {
 		writeJSON(w, http.StatusForbidden, map[string]any{"error": "ADMIN_TOKEN is not configured"})