ci(config): configure CI environment and optimize function memory

- Set FFMPEG_BIN and FFPROBE_BIN environment variables in Playwright workflow
- Reduce memory allocation for audiobook and whisper API routes to 1024MB

.github/workflows/playwright.yml

@@ -8,6 +8,9 @@ jobs:
   e2e-testing:
     timeout-minutes: 60
     runs-on: ubuntu-latest
+    env:
+      FFMPEG_BIN: /usr/bin/ffmpeg
+      FFPROBE_BIN: /usr/bin/ffprobe
     steps:
     - uses: actions/checkout@v4
     - uses: actions/setup-node@v4

vercel.json

@@ -2,10 +2,10 @@
   "$schema": "https://openapi.vercel.sh/vercel.json",
   "functions": {
     "app/api/audiobook/route.ts": {
-      "memory": 3009
+      "memory": 1024
     },
     "app/api/whisper/route.ts": {
-      "memory": 3009
+      "memory": 1024
     }
   }
 }