feat(logging): make error-logs-max-files configurable

- Add ErrorLogsMaxFiles config field with default value 10
- Support hot-reload via config file changes
- Add Management API: GET/PUT/PATCH /v0/management/error-logs-max-files
- Maintain SDK backward compatibility with NewFileRequestLogger (3 params)
- Add NewFileRequestLoggerWithOptions for custom error log retention

When request logging is disabled, forced error logs are retained up to
the configured limit. Set to 0 to disable cleanup.

sdk/logging/request_logger.go

@@ -3,6 +3,8 @@ package logging
 
 import internallogging "github.com/router-for-me/CLIProxyAPI/v6/internal/logging"
 
+const defaultErrorLogsMaxFiles = 10
+
 // RequestLogger defines the interface for logging HTTP requests and responses.
 type RequestLogger = internallogging.RequestLogger
 
@@ -12,7 +14,12 @@ type StreamingLogWriter = internallogging.StreamingLogWriter
 // FileRequestLogger implements RequestLogger using file-based storage.
 type FileRequestLogger = internallogging.FileRequestLogger
 
-// NewFileRequestLogger creates a new file-based request logger.
+// NewFileRequestLogger creates a new file-based request logger with default error log retention (10 files).
 func NewFileRequestLogger(enabled bool, logsDir string, configDir string) *FileRequestLogger {
-	return internallogging.NewFileRequestLogger(enabled, logsDir, configDir)
+	return internallogging.NewFileRequestLogger(enabled, logsDir, configDir, defaultErrorLogsMaxFiles)
+}
+
+// NewFileRequestLoggerWithOptions creates a new file-based request logger with configurable error log retention.
+func NewFileRequestLoggerWithOptions(enabled bool, logsDir string, configDir string, errorLogsMaxFiles int) *FileRequestLogger {
+	return internallogging.NewFileRequestLogger(enabled, logsDir, configDir, errorLogsMaxFiles)
 }