1.1.0: changelog, README quick start without a clone, help and in-app changelog

The quick start downloads two files and pulls the image; no clone, no
build. README figures brought up to date (it still said Astro 5, 124
tests, 16 migrations). Upgrade notes for 1.0 installs: the volume
ownership change and the basic-ftp NAT behaviour. Help page and in-app
changelog in English and German.

CONTRIBUTING.md

@@ -16,7 +16,7 @@ You need a PostgreSQL to point `DATABASE_URL` at; `docker compose up db` gives y
 one. Migrations run themselves on the first request.
 
 ```bash
-npm test          # 124 tests, no database needed
+npm test          # 130 tests, no database needed
 npx tsc --noEmit  # must be clean
 npm run build
 ```