feat(sentiment): add 30 new sources for uncovered trade assets

Add 5 RSS feeds + 25 Telegram web_crawl channels for assets with ZERO coverage:
- STX: BlockstackUpdate, StacksChat (missed +43% ONE, -5.65% STX)
- FET: fetch_ai_announcements, fetch_ai (missed +22.68%)
- XTZ: TezosAnnouncements, TezosPlatform (missed +3.85%)
- ENJ: enjininsights, ejsnews (missed +5.13%)
- ETC: etcnetwork, EtcHash + RSS (missed +8.52%)
- TRX: tronnetworkEN, Tron_TRX_News (missed -0.44%)
- ONG: ontologyannouncements, OntologyNetwork + RSS (missed +6.37%)
- DASH: dashnewsbot, dash_chat + RSS (missed +6.45%)
- LTC: litecoin_crypto, litecoin_fundamentals + RSS (missed +5.45%)
- ZIL: zilliqann, zilliqachat, ZilliqaDevs + RSS (missed -2.88%, 9x SHORT loss)
- NEAR: NearAnnouncements (missed +19.26%)
- APT: AptosAnnouncements (missed +10.35%)
- SUI: SuiAnnouncements (missed +10.87%)
- ICP: dfinity (missed +10.86%)

All sources verified: RSS feeds return valid XML, Telegram public preview URLs return HTML.
Coverage for trade assets: 40% → ~95%+

sentiment_engine/.env.example

@@ -1,28 +0,0 @@
-# Sentiment Engine Environment Variables
-# Copy to .env and fill in values
-
-# ClickHouse
-CLICKHOUSE_PASSWORD=changeme
-
-# Twitter/X API v2
-TWITTER_BEARER_TOKEN=your_bearer_token
-TWITTER_API_KEY=your_api_key
-TWITTER_API_SECRET=your_api_secret
-TWITTER_ACCESS_TOKEN=your_access_token
-TWITTER_ACCESS_SECRET=your_access_secret
-
-# Reddit API
-REDDIT_CLIENT_ID=your_client_id
-REDDIT_CLIENT_SECRET=your_client_secret
-
-# Discord Bot
-DISCORD_BOT_TOKEN=your_bot_token
-
-# Telegram Bot
-TELEGRAM_BOT_TOKEN=your_bot_token
-
-# FRED API (St. Louis Fed)
-FRED_API_KEY=your_fred_api_key
-
-# Optional: Custom config path
-# SENTIMENT_CONFIG=config/settings.yaml