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/app/config.py

@@ -33,6 +33,20 @@ class Settings(BaseSettings):
     openai_api_key: str | None = Field(default=None, validation_alias=AliasChoices("OPENAI_API_KEY"))
     openai_model: str = "gpt-4o-mini"
 
+    # Telegram Bot
+    telegram_bot_token: str | None = Field(default=None, validation_alias=AliasChoices("TELEGRAM_BOT_TOKEN"))
+    telegram_chat_id: str | None = Field(default=None, validation_alias=AliasChoices("TELEGRAM_CHAT_ID"))
+    telegram_webhook_secret: str | None = Field(default=None, validation_alias=AliasChoices("TELEGRAM_WEBHOOK_SECRET"))
+
+    # N8N API authentication
+    n8n_api_key: str | None = Field(default=None, validation_alias=AliasChoices("N8N_API_KEY"))
+
+    # Pipeline behaviour
+    pipeline_relevance_auto: int = 80    # >= this: auto-process
+    pipeline_relevance_warn: int = 60    # >= this: Telegram warning, else reject
+    pipeline_max_drafts_per_day: int = 2
+    pipeline_publish_hours: str = "9,14"  # comma-separated preferred publish hours (CET)
+
 
 @lru_cache(maxsize=1)
 def get_settings() -> Settings: