chore: monorepo - plugin, backend und hilfsdaten in einem repo

- Eltern-Ordner ist jetzt EIN Git-Repo (statt getrennter Repos).
- root .gitignore haelt Secrets (.env), node_modules, DB und Build-Artefakte raus.
- release.ps1: manueller Release (ZIP bauen + ans Backend laden).
- root README mit Struktur und Release-Ablauf.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

license-backend/.env.example

@@ -0,0 +1,27 @@
+# Copy to .env and fill in. NEVER commit the real .env.
+
+# Strong random token the n8n workflow (and you) use for admin endpoints.
+# Generate e.g. with: openssl rand -hex 32
+ADMIN_API_TOKEN=change-me-to-a-long-random-string
+
+# Public port on the host (container always listens on 8080 internally).
+PORT=8080
+
+# Comma-separated product slugs to seed on boot ("slug:Display Name").
+# Add a new entry here whenever you ship another plugin.
+SEED_PRODUCTS=gdpr-content-blocker:GDPR Content Blocker
+
+# Absolute, public base URL of this backend (behind your TLS reverse proxy).
+# Used to build the package download links handed to WordPress.
+PUBLIC_BASE_URL=https://hub.lucas-orth.de
+
+# Secret for signing time-limited download tokens. Generate with:
+#   openssl rand -hex 32
+# If left empty, ADMIN_API_TOKEN is used as a fallback.
+DOWNLOAD_SECRET=
+
+# Name of the existing Docker network that Nginx Proxy Manager runs on, so NPM
+# can reach this container as "license-backend:8080". Find it with:
+#   docker network ls
+# Typical values: npm_default, nginxproxymanager_default, proxy
+NPM_NETWORK=npm_default