switch to go backend

Backend/go.mod

@@ -0,0 +1,3 @@
+module smpark.in
+
+go 1.23

Backend/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+)
+
+func main() {
+	publicDir := "./public"
+	spaIndex := filepath.Join(publicDir, "app", "index.html")
+
+	fs := http.FileServer(http.Dir(publicDir))
+
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		// Try to serve the static file
+		path := filepath.Join(publicDir, filepath.Clean(r.URL.Path))
+		if info, err := os.Stat(path); err == nil && !info.IsDir() {
+			fs.ServeHTTP(w, r)
+			return
+		}
+
+		// Fall back to SPA index for client-side routing
+		http.ServeFile(w, r, spaIndex)
+	})
+
+	addr := ":8080"
+	log.Printf("Listening on %s", addr)
+	log.Fatal(http.ListenAndServe(addr, nil))
+}

Backend/public/.well-known/appspecific/com.tesla.3p.public-key.pem

@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEHZR4mQ31/kYqSOc2CWN7iZVmF/6f
+6Rg39BboB9K8ckj02PvNK/JheaOaQWYuNirsnfn1cGBmhE4k8p6hL2dLvQ==
+-----END PUBLIC KEY-----

Backend/public/favicon.svg

@@ -0,0 +1,4 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">
+  <rect width="100" height="100" rx="16" fill="#9370db"/>
+  <text x="50" y="68" font-family="system-ui, sans-serif" font-size="48" font-weight="bold" fill="white" text-anchor="middle">SP</text>
+</svg>