feat: Docker Compose setup untuk development & production

- docker/php/Dockerfile: PHP 8.4-FPM + GD + imagick (PECL) + semua extension Laravel
- docker/php/php.ini: upload 20MB, memory 512MB, opcache, Asia/Kuala_Lumpur
- docker/php/php-dev.ini: validate_timestamps=1, display_errors=On (dev)
- docker/nginx/default.conf: gzip, security headers, static asset caching
- docker/entrypoint.sh: tunggu MySQL → migrate → seed AdminSeeder → cache (prod)
- docker-compose.yml: dev stack — port 8003, DB host 33060, queue worker
- docker-compose.prod.yml: production overrides — storage volume, no DB port exposed
- .env.docker: template env untuk Docker (DB_HOST=db)
- .dockerignore: exclude node_modules, vendor, .env, logs

fix: testGenerate try/catch kembalikan JSON error (bukan HTML 500)
fix: loadPreview() semak r.ok, tunjuk error alert, loading spinner

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker/entrypoint.sh

@@ -0,0 +1,82 @@
+#!/bin/sh
+# ──────────────────────────────────────────────────────────────────────────────
+# eCert MBIP — Container Entrypoint
+# Jalankan sebelum php-fpm bermula:
+#   1. Tunggu MySQL
+#   2. Install Composer deps (dev sahaja)
+#   3. Generate APP_KEY jika tiada
+#   4. Migrate + seed AdminSeeder
+#   5. Storage link
+#   6. Cache (prod sahaja)
+# ──────────────────────────────────────────────────────────────────────────────
+set -e
+
+echo ""
+echo "╔══════════════════════════════════════╗"
+echo "║    eCert MBIP — Container Start      ║"
+echo "╚══════════════════════════════════════╝"
+echo ""
+
+# ── 1. Tunggu MySQL bersedia ──────────────────────────────────────────────────
+DB_HOST="${DB_HOST:-db}"
+DB_PORT="${DB_PORT:-3306}"
+DB_DATABASE="${DB_DATABASE:-ecert_mbip}"
+DB_USERNAME="${DB_USERNAME:-root}"
+DB_PASSWORD="${DB_PASSWORD:-secret}"
+
+echo "⏳ Menunggu MySQL di ${DB_HOST}:${DB_PORT}..."
+
+until mysqladmin ping \
+    -h "${DB_HOST}" \
+    -P "${DB_PORT}" \
+    -u "${DB_USERNAME}" \
+    --password="${DB_PASSWORD}" \
+    --silent 2>/dev/null; do
+    printf "."
+    sleep 2
+done
+echo ""
+echo "✓ MySQL bersedia."
+
+# ── 2. Pasang Composer dependencies (development sahaja) ─────────────────────
+if [ "${APP_ENV}" != "production" ] && [ ! -d /var/www/vendor ]; then
+    echo "📦 Memasang Composer dependencies (dev)..."
+    composer install \
+        --no-interaction \
+        --no-progress \
+        --prefer-dist
+fi
+
+# ── 3. Generate APP_KEY jika kosong ───────────────────────────────────────────
+if [ -z "${APP_KEY}" ] || [ "${APP_KEY}" = "" ]; then
+    echo "🔑 Menjana APP_KEY..."
+    php artisan key:generate --force
+fi
+
+# ── 4. Database migration ─────────────────────────────────────────────────────
+echo "🗄  Menjalankan migration..."
+php artisan migrate --force
+
+# Seed admin account (idempotent — guna firstOrCreate)
+echo "👤 Seeding AdminSeeder..."
+php artisan db:seed --class=AdminSeeder --force
+
+# ── 5. Storage symbolic link ──────────────────────────────────────────────────
+php artisan storage:link 2>/dev/null || true
+
+# ── 6. Cache (production sahaja) ──────────────────────────────────────────────
+if [ "${APP_ENV}" = "production" ]; then
+    echo "⚡ Caching config, routes, views..."
+    php artisan config:cache
+    php artisan route:cache
+    php artisan view:cache
+    php artisan event:cache
+    # Opcache: matikan validate_timestamps untuk prestasi
+    # (sudah dikonfigur dalam php.ini prod)
+fi
+
+echo ""
+echo "✅ Aplikasi bersedia."
+echo ""
+
+exec "$@"