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>

navigation/router.go

@@ -0,0 +1,157 @@
+package navigation
+
+import (
+	"strings"
+
+	"git.flowmade.one/flowmade-one/iris/reactive"
+	"git.flowmade.one/flowmade-one/iris/ui"
+)
+
+type RouteGuard func(route *Route, params map[string]string) bool
+
+type Route struct {
+	Path    string
+	Handler func(params map[string]string) ui.View
+	Guards  []RouteGuard
+	parts   []string
+	params  []string
+}
+
+type Router struct {
+	routes      []Route
+	currentPath *reactive.Signal[string]
+	currentView *reactive.Signal[ui.View]
+	notFound    func() ui.View
+}
+
+func NewRouter(routes []Route) *Router {
+	currentPath := reactive.NewSignal("")
+	currentView := reactive.NewSignal(ui.NewView())
+
+	router := &Router{
+		routes:      make([]Route, len(routes)),
+		currentPath: &currentPath,
+		currentView: &currentView,
+		notFound:    defaultNotFound,
+	}
+
+	// Parse route patterns
+	for i, route := range routes {
+		parsedRoute := route
+		parsedRoute.parts, parsedRoute.params = parseRoute(route.Path)
+		router.routes[i] = parsedRoute
+	}
+
+	return router
+}
+
+func (r *Router) SetNotFoundHandler(handler func() ui.View) {
+	r.notFound = handler
+}
+
+func (r *Router) Navigate(path string) {
+	r.currentPath.Set(path)
+	r.updateView(path)
+}
+
+func (r *Router) GetCurrentPath() string {
+	return r.currentPath.Get()
+}
+
+func (r *Router) GetCurrentView() ui.View {
+	return r.currentView.Get()
+}
+
+func (r *Router) updateView(path string) {
+	for _, route := range r.routes {
+		if params := r.matchRoute(&route, path); params != nil {
+			// Check guards
+			if r.checkGuards(&route, params) {
+				view := route.Handler(params)
+				r.currentView.Set(view)
+				return
+			}
+		}
+	}
+
+	// No route matched or guards failed
+	r.currentView.Set(r.notFound())
+}
+
+func (r *Router) matchRoute(route *Route, path string) map[string]string {
+	// Strip query parameters for route matching
+	if queryIndex := strings.Index(path, "?"); queryIndex != -1 {
+		path = path[:queryIndex]
+	}
+
+	pathParts := strings.Split(strings.Trim(path, "/"), "/")
+	if len(pathParts) == 1 && pathParts[0] == "" {
+		pathParts = []string{} // Handle root path
+	}
+
+	if len(pathParts) != len(route.parts) {
+		return nil
+	}
+
+	params := make(map[string]string)
+	paramIndex := 0
+
+	for i, routePart := range route.parts {
+		if strings.HasPrefix(routePart, ":") {
+			// This is a parameter
+			if paramIndex < len(route.params) {
+				params[route.params[paramIndex]] = pathParts[i]
+				paramIndex++
+			}
+		} else {
+			// Static part must match exactly
+			if routePart != pathParts[i] {
+				return nil
+			}
+		}
+	}
+
+	return params
+}
+
+func (r *Router) checkGuards(route *Route, params map[string]string) bool {
+	for _, guard := range route.Guards {
+		if !guard(route, params) {
+			return false
+		}
+	}
+	return true
+}
+
+func parseRoute(path string) ([]string, []string) {
+	var params []string
+	parts := strings.Split(strings.Trim(path, "/"), "/")
+	if len(parts) == 1 && parts[0] == "" {
+		parts = []string{} // Handle root path
+	}
+
+	// Find parameters like :id, :name, etc.
+	for _, part := range parts {
+		if strings.HasPrefix(part, ":") {
+			paramName := part[1:] // Remove the ':'
+			// Simple validation: param name should start with letter
+			if len(paramName) > 0 && isLetter(paramName[0]) {
+				params = append(params, paramName)
+			}
+		}
+	}
+
+	return parts, params
+}
+
+// isLetter checks if a byte is a letter
+func isLetter(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z')
+}
+
+func defaultNotFound() ui.View {
+	return ui.VerticalGroup(
+		ui.TextFromString("404 - Page Not Found").Color("#ff4444"),
+		ui.TextFromString("The requested page could not be found.").Color("#666"),
+	)
+}