cmd/pkgserver: move ui internal

This avoids inadvertently exporting a go package. This change also cleans up generate layout.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/pkgserver/internal/ui/ui.go

@@ -0,0 +1,21 @@
+// Package ui holds the static web UI.
+package ui
+
+import "net/http"
+
+func serveWebUI(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Set("Pragma", "no-cache")
+	w.Header().Set("Expires", "0")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.Header().Set("X-XSS-Protection", "1")
+	w.Header().Set("X-Frame-Options", "DENY")
+
+	http.ServeFileFS(w, r, content, "static/index.html")
+}
+
+// Register arranges for mux to serve the embedded frontend.
+func Register(mux *http.ServeMux) {
+	mux.Handle("GET /", http.FileServer(http.FS(content)))
+	mux.HandleFunc("GET /{$}", serveWebUI)
+}