1 - Fix npm install skipped on first boot due to volume-mounted node_modules

Dockerfile.dev

@@ -80,8 +80,10 @@ if [ ! -f "vendor/autoload.php" ]; then
     composer install --no-interaction
 fi
 
-# Install npm dependencies if node_modules is empty
-if [ ! -d "node_modules" ] && [ -f "package.json" ]; then
+# Install npm dependencies if node_modules lacks an install marker.
+# Can't use `[ ! -d node_modules ]` — the dir is always present because it's a
+# named volume mount. Check for npm's post-install marker file instead.
+if [ -f "package.json" ] && [ ! -f "node_modules/.package-lock.json" ]; then
     echo "Installing npm dependencies..."
     npm install
 fi