feat: add optional Adanos sentiment features

[alexander-schneider]

Summary

• add optional Adanos market sentiment helpers for ticker-level feature enrichment
• normalize Reddit, X, News, and Polymarket stock sentiment payloads into adanos_* feature columns
• document how to merge sentiment features with existing AmpyFin price data

Design notes

• no changes to core training, backtesting, broker, or execution flows
• no new runtime dependency; the API helper uses the Python standard library plus existing pandas usage
• Adanos is only used when callers explicitly provide ADANOS_API_KEY or pass api_key

Tests

• python -m pytest tests/test_adanos_sentiment.py -q -> 5 passed
• python -m pytest tests/test_common_utils.py -q -> 25 passed
• black --check utilities/adanos_sentiment.py tests/test_adanos_sentiment.py
• isort --check-only utilities/adanos_sentiment.py tests/test_adanos_sentiment.py
• flake8 utilities/adanos_sentiment.py tests/test_adanos_sentiment.py --max-line-length=160 --ignore=E203,W503,E231,E402
• python -m pytest -q currently reaches the existing suite but fails one unrelated yfinance log-string assertion in dbs/tests/test_store_price_data.py::test_download_OHLCV_invalid_ticker: current yfinance logs possibly delisted; no timezone found instead of the expected YFTzMissingError.