fix(frontend): .env reaches the build for $env/static, the runtime image stays without it; eslint + prettier as an alternative to biome; image named with dashes

template/{{ part_dir }}/Makefile.jinja

@@ -1,5 +1,5 @@
 COMPOSE := {% if layout == 'part' %}cd .. && {% endif %}docker compose
-{% if serve != 'api' %}IMAGE := {{ project_slug }}/frontend
+{% if serve != 'api' %}IMAGE := {{ project_slug | replace('_', '-') }}/frontend
 {% endif %}changed = ! git diff --quiet $(1) -- $(2) 2>/dev/null
 stamp = { git update-ref $(1) HEAD 2>/dev/null || true; }