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>

host/server.go

@@ -0,0 +1,150 @@
+package host
+
+import (
+	"compress/gzip"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// Server provides a high-performance static file server with gzip compression
+// optimized for serving WASM applications built with the Iris framework.
+type Server struct {
+	publicDir string
+	indexFile string
+}
+
+// New creates a new Server instance
+func New(publicDir, indexFile string) *Server {
+	return &Server{
+		publicDir: publicDir,
+		indexFile: indexFile,
+	}
+}
+
+// ServeHTTP implements http.Handler interface
+// Falls back to index file when:
+// (1) Request path is not found
+// (2) Request path is a directory
+// Otherwise serves the requested file with gzip compression if supported.
+func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	p := filepath.Join(s.publicDir, filepath.Clean(r.URL.Path))
+
+	if info, err := os.Stat(p); err != nil {
+		s.serveFileWithCompression(w, r, filepath.Join(s.publicDir, s.indexFile))
+		return
+	} else if info.IsDir() {
+		s.serveFileWithCompression(w, r, filepath.Join(s.publicDir, s.indexFile))
+		return
+	}
+
+	s.serveFileWithCompression(w, r, p)
+}
+
+// serveFileWithCompression serves a file with gzip compression if supported by client
+func (s *Server) serveFileWithCompression(w http.ResponseWriter, r *http.Request, filePath string) {
+	// Check if client accepts gzip
+	if !strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
+		http.ServeFile(w, r, filePath)
+		return
+	}
+
+	// Open and read file
+	file, err := os.Open(filePath)
+	if err != nil {
+		http.Error(w, "File not found", http.StatusNotFound)
+		return
+	}
+	defer file.Close()
+
+	// Get file info for headers
+	fileInfo, err := file.Stat()
+	if err != nil {
+		http.Error(w, "Error reading file", http.StatusInternalServerError)
+		return
+	}
+
+	// Set content type based on file extension
+	contentType := getContentType(filepath.Ext(filePath))
+	w.Header().Set("Content-Type", contentType)
+
+	// Check if we should compress this file type
+	if shouldCompress(contentType) {
+		// Set gzip headers
+		w.Header().Set("Content-Encoding", "gzip")
+		w.Header().Set("Vary", "Accept-Encoding")
+
+		// Create gzip writer
+		gz := gzip.NewWriter(w)
+		defer gz.Close()
+
+		// Copy file content through gzip
+		_, err = io.Copy(gz, file)
+		if err != nil {
+			http.Error(w, "Error compressing file", http.StatusInternalServerError)
+			return
+		}
+	} else {
+		// Serve without compression
+		http.ServeContent(w, r, fileInfo.Name(), fileInfo.ModTime(), file)
+	}
+}
+
+// shouldCompress determines if the content should be compressed based on Content-Type
+func shouldCompress(contentType string) bool {
+	compressibleTypes := []string{
+		"text/html",
+		"text/css",
+		"text/javascript",
+		"application/javascript",
+		"application/json",
+		"application/wasm",
+		"text/plain",
+		"image/svg+xml",
+	}
+
+	for _, t := range compressibleTypes {
+		if strings.Contains(contentType, t) {
+			return true
+		}
+	}
+	return false
+}
+
+// getContentType returns the appropriate content type for a file extension
+func getContentType(ext string) string {
+	switch ext {
+	case ".html":
+		return "text/html; charset=utf-8"
+	case ".css":
+		return "text/css"
+	case ".js":
+		return "application/javascript"
+	case ".wasm":
+		return "application/wasm"
+	case ".json":
+		return "application/json"
+	case ".ico":
+		return "image/x-icon"
+	case ".png":
+		return "image/png"
+	case ".jpg", ".jpeg":
+		return "image/jpeg"
+	case ".gif":
+		return "image/gif"
+	case ".svg":
+		return "image/svg+xml"
+	case ".woff":
+		return "font/woff"
+	case ".woff2":
+		return "font/woff2"
+	case ".ttf":
+		return "font/ttf"
+	case ".eot":
+		return "application/vnd.ms-fontobject"
+	default:
+		return "application/octet-stream"
+	}
+}