fix(conventions): alias stdlib io, add interface checks, use go-log

- Alias stdlib `io` as `goio` in cmd/codegen/main.go to follow project conventions
- Add compile-time Node interface checks for all node types in node.go
  and Layout in layout.go
- Replace fmt.Fprintf stderr logging with go-log in cmd/codegen/main.go
- Replace fmt.Println with go-log in cmd/wasm/register.go

Co-Authored-By: Virgil <virgil@lethean.io>

cmd/codegen/main.go

@@ -9,14 +9,15 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"io"
+	goio "io"
 	"os"
 
 	"forge.lthn.ai/core/go-html/codegen"
+	log "forge.lthn.ai/core/go-log"
 )
 
-func run(r io.Reader, w io.Writer) error {
-	data, err := io.ReadAll(r)
+func run(r goio.Reader, w goio.Writer) error {
+	data, err := goio.ReadAll(r)
 	if err != nil {
 		return fmt.Errorf("codegen: reading stdin: %w", err)
 	}
@@ -31,13 +32,13 @@ func run(r io.Reader, w io.Writer) error {
 		return err
 	}
 
-	_, err = io.WriteString(w, js)
+	_, err = goio.WriteString(w, js)
 	return err
 }
 
 func main() {
 	if err := run(os.Stdin, os.Stdout); err != nil {
-		fmt.Fprintf(os.Stderr, "%s\n", err)
+		log.Error("codegen failed", "err", err)
 		os.Exit(1)
 	}
 }

cmd/wasm/register.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 
 	"forge.lthn.ai/core/go-html/codegen"
+	log "forge.lthn.ai/core/go-log"
 )
 
 // buildComponentJS takes a JSON slot map and returns the WC bundle JS string.
@@ -22,5 +23,5 @@ func buildComponentJS(slotsJSON string) (string, error) {
 }
 
 func main() {
-	fmt.Println("go-html WASM module — build with GOOS=js GOARCH=wasm")
+	log.Info("go-html WASM module — build with GOOS=js GOARCH=wasm")
 }

go.mod

@@ -4,6 +4,7 @@ go 1.26.0
 
 require (
 	forge.lthn.ai/core/go-i18n v0.1.4
+	forge.lthn.ai/core/go-log v0.0.4
 	github.com/stretchr/testify v1.11.1
 )
 

go.sum

@@ -2,6 +2,8 @@ forge.lthn.ai/core/go-i18n v0.1.4 h1:zOHUUJDgRo88/3tj++kN+VELg/buyZ4T2OSdG3HBbLQ
 forge.lthn.ai/core/go-i18n v0.1.4/go.mod h1:aDyAfz7MMgWYgLkZCptfFmZ7jJg3ocwjEJ1WkJSvv4U=
 forge.lthn.ai/core/go-inference v0.1.4 h1:fuAgWbqsEDajHniqAKyvHYbRcBrkGEiGSqR2pfTMRY0=
 forge.lthn.ai/core/go-inference v0.1.4/go.mod h1:jfWz+IJX55wAH98+ic6FEqqGB6/P31CHlg7VY7pxREw=
+forge.lthn.ai/core/go-log v0.0.4 h1:KTuCEPgFmuM8KJfnyQ8vPOU1Jg654W74h8IJvfQMfv0=
+forge.lthn.ai/core/go-log v0.0.4/go.mod h1:r14MXKOD3LF/sI8XUJQhRk/SZHBE7jAFVuCfgkXoZPw=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=

layout.go

@@ -2,6 +2,9 @@ package html
 
 import "strings"
 
+// Compile-time interface check.
+var _ Node = (*Layout)(nil)
+
 // slotMeta holds the semantic HTML mapping for each HLCRF slot.
 type slotMeta struct {
 	tag  string

node.go

@@ -15,6 +15,18 @@ type Node interface {
 	Render(ctx *Context) string
 }
 
+// Compile-time interface checks.
+var (
+	_ Node = (*rawNode)(nil)
+	_ Node = (*elNode)(nil)
+	_ Node = (*textNode)(nil)
+	_ Node = (*ifNode)(nil)
+	_ Node = (*unlessNode)(nil)
+	_ Node = (*entitledNode)(nil)
+	_ Node = (*switchNode)(nil)
+	_ Node = (*eachNode[any])(nil)
+)
+
 // voidElements is the set of HTML elements that must not have a closing tag.
 var voidElements = map[string]bool{
 	"area":   true,