feat: enhance security with IP banning, ownership checks, and SSRF protection

Add comprehensive security improvements across the application:

- **IP-based login protection**: Implement IP ban system tracking login failures, auto-banning after threshold exceeded
- **Ownership verification**: Add userID parameter to Delete/Update operations for posts and comments to prevent unauthorized modifications
- **SSRF protection**: Add URL and resolved host validation for image URLs in chat and OpenAI client
- **SQL injection prevention**: Add EscapeLikeWildcard utility to escape special characters in LIKE queries
- **HTTP security**: Configure server timeouts and add security headers middleware
- **Rate limiting**: Refactor to support configurable duration and per-endpoint rate limits for auth routes
- **Error handling**: Standardize error responses using HandleError and proper error types

internal/service/message_segment_image.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"with_you/internal/model"
+	"with_you/internal/pkg/netutil"
 )
 
 // ValidateChatMessageImageSegments 校验聊天消息中的图片段：禁止 data:/base64 内联，仅允许引用本站 S3 公开前缀下的 URL。
@@ -45,6 +46,12 @@ func (s *UploadService) ValidateChatMessageImageSegments(segments model.MessageS
 		if u.Host == "" {
 			return fmt.Errorf("图片地址无效")
 		}
+		if err := netutil.ValidateURL(urlStr); err != nil {
+			return fmt.Errorf("图片地址不安全: %w", err)
+		}
+		if err := netutil.CheckResolvedHost(u.Hostname()); err != nil {
+			return fmt.Errorf("图片地址不安全: %w", err)
+		}
 
 		if !strings.HasPrefix(urlStr, prefix) {
 			return fmt.Errorf("图片必须使用本站上传接口生成的资源地址")