feat: guna MySQL external — host.docker.internal (dev) & 172.17.200.16 (prod)

- Buang service db dan volume dbdata dari compose files
- dev: extra_hosts host.docker.internal:host-gateway → capai MySQL Windows host
- prod: IP terus 172.17.200.16, tiada extra_hosts diperlukan
- .env.docker: DB_HOST=host.docker.internal dengan nota untuk production
- entrypoint.sh: default DB_HOST → host.docker.internal

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

docker/entrypoint.sh

@@ -18,7 +18,7 @@ echo "╚═══════════════════════
 echo ""
 
 # ── 1. Tunggu MySQL bersedia ──────────────────────────────────────────────────
-DB_HOST="${DB_HOST:-db}"
+DB_HOST="${DB_HOST:-host.docker.internal}"
 DB_PORT="${DB_PORT:-3306}"
 DB_DATABASE="${DB_DATABASE:-ecert_mbip}"
 DB_USERNAME="${DB_USERNAME:-root}"