Initial iris repository structure

WASM reactive UI framework for Go:
- reactive/ - Signal[T], Effect, Runtime
- ui/ - Button, Text, Input, View, Canvas, SVG components
- navigation/ - Router, guards, history management
- auth/ - OIDC client for WASM applications
- host/ - Static file server

Extracted from arcadia as open-source component.

Co-Authored-By: Claude <noreply@anthropic.com>

ui/view.go

@@ -0,0 +1,29 @@
+package ui
+
+import "git.flowmade.one/flowmade-one/iris/internal/element"
+
+type View struct {
+	e element.Element
+}
+
+func (v View) Child(child View) View {
+	v.e.Child(child.e)
+	return v
+}
+
+func NewView() View {
+	e := element.NewElement("div")
+	e.JustifyItems("center")
+	e.AlignItems("center")
+	return View{e}
+}
+
+// NewViewFromElement creates a View from an element (for advanced use cases)
+func NewViewFromElement(e element.Element) View {
+	return View{e}
+}
+
+// Element returns the underlying element (for advanced use cases)
+func (v View) Element() element.Element {
+	return v.e
+}