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/route/rules/error_format_test.go

@@ -0,0 +1,23 @@
+package rules
+
+import (
+	"testing"
+
+	gperr "github.com/yusing/goutils/errs"
+)
+
+func TestErrorFormat(t *testing.T) {
+	var rules Rules
+	err := parseRules(`
+- on: error 405
+  do: error 405 error
+- on: header too many args
+  do: error 405 error
+- name: missing do
+  on: status 200
+- on: header X-Header
+  do: set invalid_command
+- do: set resp_body "{{ .Request.Method {{ .Request.URL.Path }}"
+`, &rules)
+	gperr.LogError("error", err)
+}