test(bench): corpus staging script + gitignore for bench-corpus (parakeet bake-off)

.gitignore

@@ -46,4 +46,7 @@ packaging/npu-runtime/*.zip
 # --features vulkan build (bundled into the installer); a redistributable blob,
 # not committed.
 src-tauri/vulkan-1.dll
-MEMORY.md
+MEMORY.md
+# ASR bench corpus (test_parakeet branch): LibriSpeech-derived WAVs + refs,
+# staged by scripts/bench/fetch-corpus.ps1 — audio never enters the repo.
+bench-corpus/