refactor: upgrade to Go 1.26 and modernize code idioms

- Replace `interface{}` with `any` type alias across all packages
- Use built-in `min()`/`max()` for parameter clamping
- Use `slices.SortFunc`, `slices.Min`, `slices.Max` for cleaner code
- Use `strings.Cut()` for simpler string parsing in auth middleware
- Use `errors.Is()` for proper error comparison in handlers
- Update dependencies: golang.org/x/image 0.37.0 -> 0.38.0
- Add Wire code generation guidelines to ARCHITECTURE.md
- Disable Go cache in CI build workflow

internal/handler/admin_dashboard_handler.go

@@ -36,14 +36,9 @@ func (h *AdminDashboardHandler) GetStats(c *gin.Context) {
 // GetUserActivityTrend 获取用户活跃度趋势
 // GET /api/v1/admin/dashboard/user-activity
 func (h *AdminDashboardHandler) GetUserActivityTrend(c *gin.Context) {
-	// 解析天数参数，默认7天
+	// 解析天数参数，默认7天，限制在1-30天
 	days, _ := strconv.Atoi(c.DefaultQuery("days", "7"))
-	if days <= 0 {
-		days = 7
-	}
-	if days > 30 {
-		days = 30
-	}
+	days = min(max(days, 1), 30)
 
 	trend, err := h.dashboardService.GetUserActivityTrend(c.Request.Context(), days)
 	if err != nil {
@@ -69,14 +64,9 @@ func (h *AdminDashboardHandler) GetContentStats(c *gin.Context) {
 // GetPendingContent 获取待审核内容
 // GET /api/v1/admin/dashboard/pending-content
 func (h *AdminDashboardHandler) GetPendingContent(c *gin.Context) {
-	// 解析limit参数，默认10条
+	// 解析limit参数，默认10条，限制在1-50条
 	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "10"))
-	if limit <= 0 {
-		limit = 10
-	}
-	if limit > 50 {
-		limit = 50
-	}
+	limit = min(max(limit, 1), 50)
 
 	content, err := h.dashboardService.GetPendingContent(c.Request.Context(), limit)
 	if err != nil {