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/repository/material_repo.go

@@ -3,6 +3,7 @@
 import (
 	"with_you/internal/dto"
 	"with_you/internal/model"
+	"with_you/internal/pkg/utils"
 
 	"gorm.io/gorm"
 )
@@ -119,7 +120,7 @@ func (r *materialFileRepository) List(params dto.MaterialFileQueryParams) ([]*mo
 		query = query.Where("status = ?", params.Status)
 	}
 	if params.Keyword != "" {
-		keyword := "%" + params.Keyword + "%"
+		keyword := "%" + utils.EscapeLikeWildcard(params.Keyword) + "%"
 		query = query.Where("title LIKE ? OR description LIKE ?", keyword, keyword)
 	}
 
@@ -223,7 +224,7 @@ func (r *materialFileRepository) Search(keyword string, page, pageSize int) ([]*
 
 	query := r.db.Model(&model.MaterialFile{}).Where("status = ?", model.MaterialStatusActive)
 	if keyword != "" {
-		kw := "%" + keyword + "%"
+		kw := "%" + utils.EscapeLikeWildcard(keyword) + "%"
 		query = query.Where("title LIKE ? OR description LIKE ?", kw, kw)
 	}