refactor: cleanup unused code and simplify internal packages

This commit performs a significant cleanup of the codebase by removing unused functions, methods, and entire files across various internal modules. This reduces technical debt and simplifies the project structure.

Key changes include:
- **cache**: Removed unused cache key generators and metrics snapshots.
- **dto**: Removed redundant converter functions and segment creation helpers.
- **middleware**: Deleted the unused `logger.go` middleware and simplified `ratelimit.go` and `casbin.go`.
- **model**: Removed unused ID helpers, database closing functions, and batch decryption logic.
- **pkg**: Cleaned up unused utility functions in `circuitbreaker`, `crypto`, `cursor`, `hook`, and `utils`.
- **service**: Deleted `account_cleanup_service.go` and removed unused helper functions in `log_cleanup_service.go` and `sensitive_service.go`.
- **repository**: Removed unused private loading methods in `comment_repo.go`.

internal/pkg/utils/validator.go

@@ -2,7 +2,6 @@ package utils
 
 import (
 	"regexp"
-	"strings"
 )
 
 // ValidateEmail 验证邮箱
@@ -43,39 +42,6 @@ func ValidatePassword(password string) bool {
 	return hasUpper && hasLower && hasDigit
 }
 
-// ValidatePasswordWithDetail 验证密码强度并返回详细信息
-func ValidatePasswordWithDetail(password string) (bool, string) {
-	if len(password) < 8 {
-		return false, "密码长度至少8位"
-	}
-	if len(password) > 50 {
-		return false, "密码长度不能超过50位"
-	}
-
-	var hasUpper, hasLower, hasDigit bool
-	for _, c := range password {
-		switch {
-		case 'A' <= c && c <= 'Z':
-			hasUpper = true
-		case 'a' <= c && c <= 'z':
-			hasLower = true
-		case '0' <= c && c <= '9':
-			hasDigit = true
-		}
-	}
-
-	if !hasUpper {
-		return false, "密码必须包含大写字母"
-	}
-	if !hasLower {
-		return false, "密码必须包含小写字母"
-	}
-	if !hasDigit {
-		return false, "密码必须包含数字"
-	}
-
-	return true, ""
-}
 
 // ValidatePhone 验证手机号
 func ValidatePhone(phone string) bool {
@@ -84,13 +50,3 @@ func ValidatePhone(phone string) bool {
 	return matched
 }
 
-// SanitizeHTML 清理HTML，防止XSS攻击
-func SanitizeHTML(input string) string {
-	input = strings.ReplaceAll(input, "&", "&amp;")
-	input = strings.ReplaceAll(input, "<", "&lt;")
-	input = strings.ReplaceAll(input, ">", "&gt;")
-	input = strings.ReplaceAll(input, "\"", "&quot;")
-	input = strings.ReplaceAll(input, "'", "&#x27;")
-	input = strings.ReplaceAll(input, "/", "&#x2F;")
-	return input
-}