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/core.go

@@ -0,0 +1,69 @@
+package navigation
+
+import (
+	"strings"
+)
+
+// Core routing logic separated from UI dependencies
+
+type RoutePattern struct {
+	parts  []string
+	params []string
+}
+
+func CompileRoutePattern(path string) RoutePattern {
+	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 && isLetterCore(paramName[0]) {
+				params = append(params, paramName)
+			}
+		}
+	}
+	
+	return RoutePattern{parts, params}
+}
+
+func MatchRoute(routePattern RoutePattern, path string) map[string]string {
+	pathParts := strings.Split(strings.Trim(path, "/"), "/")
+	if len(pathParts) == 1 && pathParts[0] == "" {
+		pathParts = []string{} // Handle root path
+	}
+	
+	if len(pathParts) != len(routePattern.parts) {
+		return nil
+	}
+	
+	params := make(map[string]string)
+	paramIndex := 0
+	
+	for i, routePart := range routePattern.parts {
+		if strings.HasPrefix(routePart, ":") {
+			// This is a parameter
+			if paramIndex < len(routePattern.params) {
+				params[routePattern.params[paramIndex]] = pathParts[i]
+				paramIndex++
+			}
+		} else {
+			// Static part must match exactly
+			if routePart != pathParts[i] {
+				return nil
+			}
+		}
+	}
+	
+	return params
+}
+
+// isLetterCore checks if a byte is a letter
+func isLetterCore(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z')
+}