Summary

This PR adds an optional Adanos Market Sentiment data provider for US stock ticker sentiment enrichment.

The integration is disabled by default and only becomes active when ADANOS_API_KEY is configured. Without a key, the new endpoint returns enabled=false and QuantDinger continues to work normally.

Changes

• Adds fetch_adanos_market_sentiment() as a fail-open backend provider.
• Adds authenticated endpoint GET /api/global-market/adanos-sentiment?tickers=AAPL,TSLA&source=reddit&days=7.
• Supports Adanos sentiment sources: reddit, x, news, and polymarket.
• Normalizes common compare fields plus source-specific activity metrics such as subreddit_count, unique_tweets, source_count, trade_count, market_count, and total_liquidity.
• Adds ADANOS_API_KEY, ADANOS_SENTIMENT_SOURCE, ADANOS_API_BASE_URL, and ADANOS_API_TIMEOUT to the environment template.
• Documents the optional setup in the backend and root docs.
• Adds provider and endpoint tests for disabled mode, request normalization, fail-open HTTP errors, non-finite values, auth enforcement, and invalid route input.

Validation

• python3 -m pytest tests/ -q
• python3 -m py_compile app/data_providers/adanos_sentiment.py app/routes/global_market.py tests/test_data_providers.py tests/test_global_market_adanos.py
• git diff --check