feat(rules): add post-request rules system with response manipulation (#160)

* Add comprehensive post-request rules support for response phase
* Enable response body, status, and header manipulation via set commands
* Refactor command handlers to support both request and response phases
* Implement response modifier system for post-request template execution
* Support response-based rule matching with status and header checks
* Add comprehensive benchmarks for matcher performance
* Refactor authentication and proxying commands for unified error handling
* Support negated conditions with !
* Enhance error handling, error formatting and validation
* Routes: add `rule_file` field with rule preset support
* Environment variable substitution: now supports variables without `GODOXY_` prefix

* new conditions:
  * `on resp_header <key> [<value>]`
  * `on status <status>`
* new commands:
  * `require_auth`
  * `set resp_header <key> <template>`
  * `set resp_body <template>`
  * `set status <code>`
  * `log <level> <path> <template>`
  * `notify <level> <provider> <title_template> <body_template>`

internal/notif/body.go

@@ -20,10 +20,11 @@ type (
 )
 
 type (
-	FieldsBody  []LogField
-	ListBody    []string
-	MessageBody string
-	errorBody   struct {
+	FieldsBody       []LogField
+	ListBody         []string
+	MessageBody      string
+	MessageBodyBytes []byte
+	errorBody        struct {
 		Error error
 	}
 )
@@ -98,7 +99,15 @@ func (m MessageBody) Format(format LogFormat) ([]byte, error) {
 	case LogFormatRawJSON:
 		return sonic.Marshal(m)
 	}
-	return m.Format(LogFormatMarkdown)
+	return []byte(m), nil
+}
+
+func (m MessageBodyBytes) Format(format LogFormat) ([]byte, error) {
+	switch format {
+	case LogFormatRawJSON:
+		return sonic.Marshal(string(m))
+	}
+	return m, nil
 }
 
 func (e errorBody) Format(format LogFormat) ([]byte, error) {