feat: refine assistant logic and update docs

scripts/qwen-check.sh

@@ -4,8 +4,13 @@ set -euo pipefail
 ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 cd "$ROOT"
 
+PYTHON_BIN="python3"
+if [ -x "$ROOT/.venv/bin/python" ]; then
+  PYTHON_BIN="$ROOT/.venv/bin/python"
+fi
+
 echo "[qwen-check] Python syntax compile check"
-python -m compileall app run.py >/dev/null
+"$PYTHON_BIN" -m compileall app run.py >/dev/null
 
 echo "[qwen-check] Optional ruff check"
 if command -v ruff >/dev/null 2>&1; then