fix: add verification and playback safeguards

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+
+      - name: Install Python dependencies
+        run: python -m pip install -e ".[dev]"
+
+      - name: Check Python syntax
+        run: python -m py_compile stream_server.py ascii_video_player2.py
+
+      - name: Check JavaScript syntax
+        run: node --check app.js
+
+      - name: Run tests
+        run: python -m pytest -q