* chore(deps): update submodule goutils
* docs(http): remove default client from README.md
* refactor(rules): introduce block DSL, phase-based execution, and flow validation
- add block syntax parser/scanner with nested @blocks and elif/else support
- restructure rule execution into explicit pre/post phases with phase flags
- classify commands by phase and termination behavior
- enforce flow semantics (default rule handling, dead-rule detection)
- expand HTTP flow coverage with block + YAML parity tests and benches
- refresh rules README/spec and update playground/docs integration
- Default rules act as fallback handlers that execute only when no matching non-default rule exists in the pre phase
- IfElseBlockCommand now returns early when a condition matches with a nil Do block, instead of falling through to else blocks
- Add nil check for auth handler to allow requests when no auth is configured
* fix(rules): buffer log output before writing to stdout/stderr
* refactor(api/rules): remove IsResponseRule field from ParsedRule and related logic
* docs(rules): update examples to use block syntax
This is a large-scale refactoring across the codebase that replaces the custom
`gperr.Error` type with Go's standard `error` interface. The changes include:
- Replacing `gperr.Error` return types with `error` in function signatures
- Using `errors.New()` and `fmt.Errorf()` instead of `gperr.New()` and `gperr.Errorf()`
- Using `%w` format verb for error wrapping instead of `.With()` method
- Replacing `gperr.Subject()` calls with `gperr.PrependSubject()`
- Converting error logging from `gperr.Log*()` functions to zerolog's `.Err().Msg()` pattern
- Update NewLogger to handle multiline error message
- Updating `goutils` submodule to latest commit
This refactoring aligns with Go idioms and removes the dependency on
custom error handling abstractions in favor of standard library patterns.
