feat: add optional adanos market sentiment custom data example

[alexander-schneider]

Summary

This PR adds an optional Python custom data example for consuming structured Adanos market sentiment snapshots in LEAN.

It includes:

• a new Algorithm.Python/AdanosMarketSentimentAlgorithm.py example
• a project entry in QuantConnect.Algorithm.Python.csproj
• focused PythonDataTests coverage for the new custom data type

Why

LEAN already has strong support for custom data via AddData<T> / PythonData, and this change keeps the integration in that example-oriented path rather than introducing a new core data provider.

Adanos is used here as structured alternative data for equities:

• current buzz score
• bullish percentage
• sentiment score
• simple activity / coverage counts

Design notes

• The example is strictly optional and parameter-driven.
• No requests are made unless adanos-api-key is provided.
• The example now exits early outside live mode, because querying a current REST endpoint in a historical backtest would introduce look-ahead bias. The intended historical workflow is to persist daily snapshots first and then replay them from a local file or ObjectStore.
• The core LEAN data feed and provider stack are untouched.

Parameters

• adanos-api-key – required to enable requests
• adanos-source – one of news, reddit, x, polymarket
• adanos-lookback-days – lookback window passed through to the stock sentiment endpoint

Validation

Added focused tests in Tests/Python/PythonDataTests.cs for:

• request header propagation
• structured payload parsing
• unsupported source fallback
• found=false null handling

[AlexCatarino]

Hi @alexander-schneider,
Do you represent Adanos? If you do, contact us at support@quantconnect.com. This dataset is better suited to /datasets than to this repository. Otherwise, we could find a place for it in the Docs, or you could place a working example in /strategies.

[alexander-schneider]

Thanks, wrote you an email :)