Untrack the emitted vite config, and select biome's files by extension

vite.config.js and vite.config.d.ts are tsc output of vite.config.ts, emitted
next to the source when the composite tsconfig.node.json is built. Nothing
reads them — and vite picks a vite.config.js ahead of the .ts, so the committed
copy was quietly shadowing the real config. Gitignore both.

The biome hook selected by the frontend/ prefix and passed the staged paths on,
but `bun run lint` runs in frontend/, so biome saw frontend/frontend/… and
reported an internal io error for every staged file. The script already lints
the whole tree, so stop passing filenames and let the pattern — now the
extensions biome parses — decide only whether the hook runs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CL9zvnnvcp1mvA8o7impxk

frontend/vite.config.d.ts

@@ -1,2 +0,0 @@
-declare const _default: import("vite").UserConfig
-export default _default

frontend/vite.config.js

@@ -1,25 +0,0 @@
-import path from "node:path"
-import tailwindcss from "@tailwindcss/vite"
-import { tanstackRouter } from "@tanstack/router-plugin/vite"
-import react from "@vitejs/plugin-react-swc"
-import { defineConfig } from "vite"
-// https://vitejs.dev/config/
-export default defineConfig({
-  // A portal serves this bundle under a path of its own and caches one copy
-  // for every instance, so asset URLs have to be absolute under that
-  // prefix. Unset — every ordinary build — this stays "/".
-  base: process.env.VITE_BASE || "/",
-  resolve: {
-    alias: {
-      "@": path.resolve(__dirname, "./src"),
-    },
-  },
-  plugins: [
-    tanstackRouter({
-      target: "react",
-      autoCodeSplitting: true,
-    }),
-    react(),
-    tailwindcss(),
-  ],
-})