feat(automation): autonomous pipeline with Telegram bot and N8N integration

- Add full auto pipeline: RSS ingest → GPT relevance score → AI rewrite → WP draft
- Add Telegram bot with inline buttons (rewrite/discard/override) and commands (/run, /rejected, /status)
- Add smart publish scheduler: max 2 drafts/day, spread over week (09:00 & 14:00 CET)
- Add N8N API endpoints (/api/n8n/pipeline, /api/n8n/ingest) with X-API-Key auth
- Add GPT-based relevance scoring (0-100) for VanLife/Camping/Outdoor topics
- Remove Ampel risk-level policy check from ingestion (all enabled feeds are used)
- Add Telegram webhook endpoint and setup endpoint
- Add delete_wp_post() for Telegram discard action
- Add DB migrations for relevance_score and scheduled_publish_at columns
- Update .env.example with all new configuration variables
- Add docs/AUTOMATION.md with full setup and usage documentation

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

backend/.env.example

@@ -1,3 +1,4 @@
+# ─── App ────────────────────────────────────────────────────────────────────
 APP_ENV=development
 APP_NAME=rss-news-backend
 APP_SECRET_KEY=replace-with-a-long-random-secret
@@ -8,3 +9,37 @@ APP_ADMIN_PASSWORD=change-me
 
 SESSION_COOKIE_NAME=rss_news_session
 SESSION_MAX_AGE_SECONDS=28800
+
+# ─── WordPress ──────────────────────────────────────────────────────────────
+WP_BASE_URL=https://your-site.tld
+WP_USERNAME=your-wp-username
+WP_PASSWORD=your-wp-app-password
+# Status für neue Beiträge: draft | future | publish
+WORDPRESS_DEFAULT_STATUS=draft
+
+# ─── OpenAI ─────────────────────────────────────────────────────────────────
+OPENAI_API_KEY=sk-...
+# gpt-4o-mini empfohlen (Kosten/Qualität)
+OPENAI_MODEL=gpt-4o-mini
+
+# ─── Telegram Bot ────────────────────────────────────────────────────────────
+# Bot-Token von @BotFather
+TELEGRAM_BOT_TOKEN=123456789:ABC...
+# Chat-ID deines persönlichen Chats oder einer Gruppe
+TELEGRAM_CHAT_ID=123456789
+# Zufälliger Secret-Token zur Webhook-Absicherung (mindestens 20 Zeichen)
+TELEGRAM_WEBHOOK_SECRET=replace-with-random-secret-min-20-chars
+
+# ─── N8N API-Key ─────────────────────────────────────────────────────────────
+# Wird von N8N im Header X-API-Key mitgeschickt
+N8N_API_KEY=replace-with-strong-random-key
+
+# ─── Pipeline-Einstellungen ──────────────────────────────────────────────────
+# Relevanz-Score >= dieser Wert: automatisch verarbeiten (0-100)
+PIPELINE_RELEVANCE_AUTO=80
+# Relevanz-Score >= dieser Wert, aber < AUTO: Telegram-Warnung senden
+PIPELINE_RELEVANCE_WARN=60
+# Maximale Drafts/Veröffentlichungen pro Tag
+PIPELINE_MAX_DRAFTS_PER_DAY=2
+# Bevorzugte Veröffentlichungszeiten (Stunden, kommagetrennt, CET)
+PIPELINE_PUBLISH_HOURS=9,14