fix(dev): stop the dev server watching .gev-cache and .gev-logs (#761)

Providers write cache files and logs into .gev-cache and .gev-logs while the app runs. A serve-only standalone plugin adds both to server.watch.ignored, so the dev watcher no longer stats them; source changes still reload.

server/standalone/unwatched-cache.js

@@ -0,0 +1,28 @@
+/**
+ * Directories the app writes to while it runs. None is source, and none
+ * should reload anything.
+ */
+const RUNTIME_WRITE_GLOBS = Object.freeze([
+  '**/.gev-cache/**',
+  '**/.gev-logs/**',
+]);
+
+/**
+ * Keep the directories the app writes to out of the dev server's file watcher.
+ *
+ * Disk-cached providers write a file per response into `.gev-cache`, and the
+ * voice debug log appends to `.gev-logs`. Left watched, each write costs the
+ * watcher stat calls on libuv's thread pool, which `getaddrinfo` shares; heavy
+ * cache writes have been seen to delay upstream DNS lookups.
+ *
+ * @returns {import('vite').Plugin} Config-only plugin; no server hooks.
+ */
+export function unwatchedRuntimeDirsPlugin() {
+  return {
+    name: 'gev-unwatched-runtime-dirs',
+    apply: 'serve',
+    config: () => ({
+      server: { watch: { ignored: [...RUNTIME_WRITE_GLOBS] } },
+    }),
+  };
+}