build: migrate manualChunks to function form for Vite 8 / Rolldown

Vite 8 switches the bundler to Rolldown, which no longer accepts the
object form of rollupOptions.output.manualChunks — it must be a function.
Convert it (same ndk/vendor split intent) and give tsconfig.node.json a
modern target/lib so vite.config.ts type-checks against String.includes.

.gitignore

@@ -48,3 +48,6 @@ skills-lock.json
 *.njsproj
 *.sln
 *.sw?
+
+# TypeScript incremental build info
+*.tsbuildinfo

tsconfig.node.json

@@ -2,6 +2,8 @@
   "compilerOptions": {
     "composite": true,
     "skipLibCheck": true,
+    "target": "ES2022",
+    "lib": ["ES2023"],
     "module": "ESNext",
     "moduleResolution": "bundler",
     "allowSyntheticDefaultImports": true

vite.config.ts

@@ -18,12 +18,14 @@ export default defineConfig(async () => ({
   build: {
     rollupOptions: {
       output: {
-        manualChunks: {
+        // Vite 8 / Rolldown requires manualChunks as a function (the object
+        // form is no longer accepted). Same intent as before:
+        manualChunks(id: string) {
           // NDK is the largest dependency (~300kB) — split it out so the
           // main bundle parses faster at startup and the chunk can be cached.
-          "ndk": ["@nostr-dev-kit/ndk"],
+          if (id.includes("node_modules/@nostr-dev-kit/ndk")) return "ndk";
           // React runtime — stable across releases, cache-friendly.
-          "vendor": ["react", "react-dom"],
+          if (id.includes("node_modules/react-dom/") || id.includes("node_modules/react/")) return "vendor";
         },
       },
     },