refactor(errs): migrate from gperr.Error to standard Go error interface

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.

internal/net/gphttp/loadbalancer/ip_hash.go

@@ -9,7 +9,6 @@ import (
 	"github.com/bytedance/gopkg/util/xxhash3"
 	"github.com/yusing/godoxy/internal/net/gphttp/middleware"
 	"github.com/yusing/godoxy/internal/types"
-	gperr "github.com/yusing/goutils/errs"
 )
 
 type ipHash struct {
@@ -28,10 +27,10 @@ func (lb *LoadBalancer) newIPHash() impl {
 	if len(lb.Options) == 0 {
 		return impl
 	}
-	var err gperr.Error
+	var err error
 	impl.realIP, err = middleware.RealIP.New(lb.Options)
 	if err != nil {
-		gperr.LogError("invalid real_ip options, ignoring", err, &impl.l)
+		impl.l.Err(err).Msg("invalid real_ip options, ignoring")
 	}
 	return impl
 }