fix(laravel): align Composer build stage with app PHP version

Use php-cli matching phpVersion instead of composer:2 (PHP 8.5), skip
artisan during dump-autoload, and fail loudly on composer install instead
of swallowing lock-file/platform errors with || true.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/build/build.service.ts

@@ -998,13 +998,15 @@ CMD ["sh", "-c", "if [ \\"$(cat /app/.mode)\\" = \\"standalone\\" ] && [ -f serv
   private laravelDockerfile(app: Application): string {
     const phpVersion = app.phpVersion || '8.3';
     const port = app.port || 80;
-    return `# --- Build stage ---
-FROM composer:2 AS composer
+    return `# --- Build stage (match production PHP version for Composer) ---
+FROM php:${phpVersion}-cli-alpine AS composer
+RUN apk add --no-cache git unzip
+COPY --from=composer:2 /usr/bin/composer /usr/bin/composer
 WORKDIR /app
 COPY composer.json composer.lock* ./
-RUN composer install --no-dev --no-scripts --no-autoloader --prefer-dist || true
+RUN composer install --no-dev --no-scripts --no-autoloader --prefer-dist --ignore-platform-reqs
 COPY . .
-RUN composer dump-autoload --optimize --no-dev
+RUN composer dump-autoload --optimize --no-dev --no-scripts
 
 # --- Production stage ---
 FROM php:${phpVersion}-fpm-alpine