fix(script): add Windows .venv/Scripts path fallback in server.sh

On Windows the venv Python binary lives at .venv/Scripts/python.exe,
not .venv/bin/python.  Fall back to the Windows path when the Unix
path does not exist so the script works cross-platform.

server.sh

@@ -15,6 +15,9 @@ set -euo pipefail
 
 ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 PYTHON="$ROOT/.venv/bin/python"
+if [ ! -f "$PYTHON" ]; then
+  PYTHON="$ROOT/.venv/Scripts/python.exe"
+fi
 ENTRY="$ROOT/main.py"
 LOG_DIR="$ROOT/logs"
 LOG_OUT="$LOG_DIR/server.log"