feat(apk): 增加公开APK管理接口和CI/CD工作流

- 新增获取最新APK版本信息和下载APK的公开接口
- 更新README文档，添加APK管理接口的使用说明
- 实现CI/CD工作流，支持自动构建和部署
- 优化APK存储逻辑，确保只保留最新APK文件

internal/handlers/handlers.go

@@ -10,7 +10,9 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 
+	"expo-updates-server-go/internal/model"
 	"expo-updates-server-go/internal/service"
 	"expo-updates-server-go/internal/storage"
 )
@@ -284,6 +286,50 @@ func (h *Handler) AdminListAPKs(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]any{"apks": apks})
 }
 
+func (h *Handler) PublicLatestAPK(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		writeJSON(w, http.StatusMethodNotAllowed, map[string]any{"error": "Expected GET."})
+		return
+	}
+	apk, err := h.svc.GetLatestAPK()
+	if err != nil {
+		writeJSON(w, http.StatusInternalServerError, map[string]any{"error": err.Error()})
+		return
+	}
+	if apk == nil {
+		writeJSON(w, http.StatusNotFound, map[string]any{"error": "No APK available"})
+		return
+	}
+	resp := model.LatestAPKResponse{
+		RuntimeVersion: apk.RuntimeVersion,
+		VersionName:    apk.RuntimeVersion,
+		Size:           apk.Size,
+		DownloadURL:    fmt.Sprintf("%s/api/apk/download?runtimeVersion=%s", h.svc.Hostname(), apk.RuntimeVersion),
+		CreatedAt:      apk.CreatedAt.Format(time.RFC3339),
+	}
+	writeJSON(w, http.StatusOK, resp)
+}
+
+func (h *Handler) PublicDownloadAPK(w http.ResponseWriter, r *http.Request) {
+	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=carrot-bbs-%s.apk", runtimeVersion))
+	http.ServeFile(w, r, apkPath)
+}
+
 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"})
@@ -328,7 +374,7 @@ func firstNonEmpty(values ...string) string {
 	return ""
 }
 
-func writeJSON(w http.ResponseWriter, code int, data map[string]any) {
+func writeJSON(w http.ResponseWriter, code int, data any) {
 	w.Header().Set("content-type", "application/json")
 	w.WriteHeader(code)
 	_ = json.NewEncoder(w).Encode(data)