chore : rename Coltura to Starseed

- Rename project name across code, configs, docs, dev/prod infra
- Dev: DOCKER_APP_NAME + POSTGRES_DB switched to starseed, containers become php-starseed-fpm / nginx-starseed / starseed-db-1
- Dev: mount nginx.conf on default.conf instead of starseed.conf to avoid alphabetical-order clash with image's default site
- Makefile: export CURRENT_UID/CURRENT_GID at top level so docker compose builds (db-reset etc.) get them
- Prod: image registry path, container_name, volumes, vhost server_name + paths, DATABASE_URL, CORS, CI workflow
- Add doc/prompt-rename-prod.md with the migration runbook for the prod server (DB rename, FS move, vhost, Let's Encrypt)

frontend/eslint.config.mjs

@@ -14,7 +14,7 @@ export default await nuxt(
         },
     },
     {
-        name: 'coltura/custom-overrides',
+        name: 'starseed/custom-overrides',
         rules: {
             // Indentation 4 espaces (convention CLAUDE.md)
             'vue/html-indent': ['error', 4],