Add native Crystal exploration port and reference tooling

vite.config.ts

@@ -0,0 +1,28 @@
+import { defineConfig } from "vite";
+
+export default defineConfig(({ mode }) => ({
+  publicDir: mode === "reference" ? "reference/public" : "public",
+  server: {
+    host: "127.0.0.1",
+    // A user ROM may sit at the repository root. Never serve it or extracted
+    // assets and the private PRET checkout as static files.
+    fs: {
+      deny: [
+        "**/*.{gb,gbc,rom,sav}",
+        "**/*.crystal-save.json",
+        "**/.reference/**",
+        "**/artifacts/**",
+        ".env",
+        ".env.*",
+        "**/.git/**",
+      ],
+    },
+  },
+  build:
+    mode === "reference"
+      ? {
+          outDir: "dist-reference",
+          rollupOptions: { input: "reference.html" },
+        }
+      : { outDir: "dist" },
+}));