fix: install PHP deps before frontend build in deploy workflow

Filament's admin.css imports from vendor/, which requires composer
dependencies to be present during the Vite build step.

Author: AdilAzhari

.github/workflows/deploy.yml

@@ -45,6 +45,16 @@ jobs:
         uses: actions/checkout@v4
 
       # ── Build frontend assets on CI runner (npm not available on server) ──
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: "8.4"
+          tools: composer:v2
+          coverage: none
+
+      - name: Install PHP dependencies
+        run: composer install --no-dev --no-interaction --optimize-autoloader --prefer-dist
+
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with: