feat(html): add dir helper

Add a Dir convenience helper for the dir attribute so RTL/text-direction markup can be applied without raw Attr calls.

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

docs/architecture.md

@@ -39,6 +39,7 @@ Accessibility-oriented helpers are also provided for common attribute patterns:
 - `AriaLabelledBy(node, ids...)`
 - `Role(node, role)`
 - `Lang(node, locale)`
+- `Dir(node, direction)`
 - `Alt(node, text)`
 - `AriaHidden(node, hidden)`
 - `TabIndex(node, index)`

node.go

@@ -208,6 +208,12 @@ func Lang(n Node, locale string) Node {
 	return Attr(n, "lang", locale)
 }
 
+// node.go: Dir sets the dir attribute on an element node.
+// Example: Dir(El("p"), "rtl").
+func Dir(n Node, direction string) Node {
+	return Attr(n, "dir", direction)
+}
+
 // node.go: Alt sets the alt attribute on an element node.
 // Example: Alt(El("img"), "Product screenshot").
 func Alt(n Node, text string) Node {

node_test.go

@@ -283,6 +283,16 @@ func TestLangHelper(t *testing.T) {
 	}
 }
 
+func TestDirHelper(t *testing.T) {
+	ctx := NewContext()
+	node := Dir(El("p", Raw("مرحبا")), "rtl")
+	got := node.Render(ctx)
+	want := `<p dir="rtl">مرحبا</p>`
+	if got != want {
+		t.Errorf("Dir() = %q, want %q", got, want)
+	}
+}
+
 func TestAltHelper(t *testing.T) {
 	ctx := NewContext()
 	node := Alt(El("img"), `A "quoted" caption`)