- Replace template syntax ({{ .Request.Method }}) with $-prefixed variables ($req_method)
- Implement custom variable parser with static ($req_method, $status_code) and dynamic ($header(), $arg(), $form()) variables
- Replace templateOrStr interface with templateString struct and ExpandVars methods
- Add parser improvements for reliable quote handling
- Add new error types: ErrUnterminatedParenthesis, ErrUnexpectedVar, ErrExpectOneOrTwoArgs
- Update all tests and help text to use new variable syntax
- Add comprehensive unit and benchmark tests for variable expansion
* 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>`
