fix: make fix-perms idempotent and persistent across container restarts

The getgrav/grav image is Debian-based and has no uid 1000 user,
causing Apache to fail switching to APACHE_RUN_USER=#1000 on restart.
fix-perms now creates the uid 1000 user if absent, sets ownership,
then gracefully reloads Apache workers so they run as uid 1000.

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

Makefile

@@ -30,7 +30,9 @@ stop:
 setup: start install-plugins fix-perms
 
 fix-perms:
+	docker exec intotheeast_grav bash -c "getent passwd 1000 > /dev/null || useradd -u 1000 -M hostuser"
 	docker exec intotheeast_grav chown -R 1000:1000 /var/www/html
+	docker exec intotheeast_grav apachectl graceful
 
 install-plugins:
 	docker exec -w /var/www/html intotheeast_grav php bin/gpm install $(shell cat plugins.txt | tr '\n' ' ') -y