fix: resolve GitHub Actions pipeline errors

- Fix Dockerfile syntax version (1.20 -> 1.4) for better compatibility
- Remove unused BUILD_TYPE ARG and final stage
- Fix shellcheck warnings in shell scripts:
  - Add set -e to build-images script
  - Quote all variables properly
  - Use POSIX-compliant arithmetic syntax in test-performance
- Ensure all scripts pass shellcheck validation

Author: mohaelmrabet

Dockerfile

@@ -1,14 +1,13 @@
-#syntax=docker/dockerfile:1.20
+#syntax=docker/dockerfile:1.4
 # Dockerfile for Magento FrankenPHP
-# Supports base and dev build targets via BUILD_TYPE ARG
+# Supports base and dev build targets
 #
 # Build examples:
-#   docker build --build-arg BUILD_TYPE=base -t magento-frankenphp:base .
-#   docker build --build-arg BUILD_TYPE=dev -t magento-frankenphp:dev .
+#   docker build --target base -t magento-frankenphp:base .
+#   docker build --target dev -t magento-frankenphp:dev .
 
 ARG PHP_VERSION=8.4
 ARG FRANKENPHP_VERSION=1.10.1
-ARG BUILD_TYPE=base
 
 FROM dunglas/frankenphp:${FRANKENPHP_VERSION}-php${PHP_VERSION} AS base
 LABEL maintainer="Mohamed El Mrabet <contact@cleatsquad.dev>"
@@ -118,5 +117,3 @@ ENV SENDMAIL_PATH=/usr/local/bin/mhsendmail \
     XDEBUG_CLIENT_PORT=9003 \
     XDEBUG_START_WITH_REQUEST=trigger \
     XDEBUG_IDEKEY=PHPSTORM
-
-FROM ${BUILD_TYPE} AS final

bin/build-images

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -e
 
 IMAGE="mohelmrabet/magento-frankenphp"
 VERSIONS="8.2 8.3 8.4"
@@ -39,18 +40,18 @@ push_all() {
 
 push_latest() {
     echo "📤 Pushing latest tags..."
-    docker tag ${IMAGE}:php8.4-fp${FP}-base ${IMAGE}:latest
-    docker tag ${IMAGE}:php8.4-fp${FP}-base ${IMAGE}:base
-    docker tag ${IMAGE}:php8.4-fp${FP}-dev ${IMAGE}:dev
-    docker push ${IMAGE}:latest
-    docker push ${IMAGE}:base
-    docker push ${IMAGE}:dev
+    docker tag "${IMAGE}:php8.4-fp${FP}-base" "${IMAGE}:latest"
+    docker tag "${IMAGE}:php8.4-fp${FP}-base" "${IMAGE}:base"
+    docker tag "${IMAGE}:php8.4-fp${FP}-dev" "${IMAGE}:dev"
+    docker push "${IMAGE}:latest"
+    docker push "${IMAGE}:base"
+    docker push "${IMAGE}:dev"
     echo "✅ Latest tags pushed!"
 }
 
 list_images() {
     echo "📦 Local images:"
-    docker images | grep ${IMAGE}
+    docker images | grep "${IMAGE}"
 }
 
 push_readme() {

bin/test-performance

@@ -22,12 +22,12 @@ PASSED=0
 FAILED=0
 
 test_result() {
-    if [ $1 -eq 0 ]; then
+    if [ "$1" -eq 0 ]; then
         echo -e "${GREEN}✓ PASS${NC}: $2"
-        ((PASSED++))
+        PASSED=$((PASSED + 1))
     else
         echo -e "${RED}✗ FAIL${NC}: $2"
-        ((FAILED++))
+        FAILED=$((FAILED + 1))
     fi
 }