refactor: Implement dependency injection for handlers and services

- Refactored AuthHandler, UserHandler, TextureHandler, ProfileHandler, CaptchaHandler, and YggdrasilHandler to use dependency injection.
- Removed direct instantiation of services and repositories within handlers, replacing them with constructor injection.
- Updated the container to initialize service instances and provide them to handlers.
- Enhanced code structure for better testability and adherence to Go best practices.

internal/service/helpers_test.go

@@ -0,0 +1,50 @@
+package service
+
+import (
+	"errors"
+	"testing"
+)
+
+// TestNormalizePagination_Basic 覆盖 NormalizePagination 的边界分支
+func TestNormalizePagination_Basic(t *testing.T) {
+	tests := []struct {
+		name         string
+		page         int
+		size         int
+		wantPage     int
+		wantPageSize int
+	}{
+		{"page 小于 1", 0, 10, 1, 10},
+		{"pageSize 小于 1", 1, 0, 1, 20},
+		{"pageSize 大于 100", 2, 200, 2, 100},
+		{"正常范围", 3, 30, 3, 30},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotPage, gotSize := NormalizePagination(tt.page, tt.size)
+			if gotPage != tt.wantPage || gotSize != tt.wantPageSize {
+				t.Fatalf("NormalizePagination(%d,%d) = (%d,%d), want (%d,%d)",
+					tt.page, tt.size, gotPage, gotSize, tt.wantPage, tt.wantPageSize)
+			}
+		})
+	}
+}
+
+// TestWrapError 覆盖 WrapError 的 nil 与非 nil 分支
+func TestWrapError(t *testing.T) {
+	if err := WrapError(nil, "msg"); err != nil {
+		t.Fatalf("WrapError(nil, ...) 应返回 nil, got=%v", err)
+	}
+
+	orig := errors.New("orig")
+	wrapped := WrapError(orig, "context")
+	if wrapped == nil {
+		t.Fatalf("WrapError 应返回非 nil 错误")
+	}
+	if wrapped.Error() == orig.Error() {
+		t.Fatalf("WrapError 应添加上下文信息, got=%v", wrapped)
+	}
+}
+
+