Redesign the interface

Deep blue-black theme with a violet-to-cyan accent, frosted floating
panels, self-hosted Inter, a welcome screen with a call to action, a
card-style inspector, accent tabs and toggles, animated progress, and
a restyled open dialog. In 3D the WebGL walls are now lit per side
with a darker foot so buildings read as solids, and the canvas clears
to transparent over the new background. Renamed to CodeNavigator.

main.go

@@ -12,6 +12,7 @@ import (
 	"io"
 	"io/fs"
 	"log"
+	"mime"
 	"net/http"
 	"os"
 	"os/exec"
@@ -71,6 +72,11 @@ type Server struct {
 	auth        map[string]*githubAuth // by session ID
 }
 
+func init() {
+	// Alpine has no /etc/mime.types, so the embedded font needs an explicit type.
+	mime.AddExtensionType(".woff2", "font/woff2")
+}
+
 func NewServer(workspace string) *Server {
 	cors := os.Getenv("CORS_ORIGIN")
 	if cors == "" || strings.ContainsAny(cors, "\r\n") {