Add Polymarket bot scaffold with Kronos adapter, decision engine, executor, and logger

[client1429]

Motivation

• Provide a minimal, modular scaffold for an automated PolyMarket trading bot to enable local development and stepwise integration of real APIs and models.
• Define configuration objects for risk, strategy, and runtime parameters to centralize tuning and safety caps.

Description

• Add a README polymarket_bot/README.md explaining the scaffold and how to run the demo with python -m polymarket_bot.main (defaults to dry_run=True).
• Add configuration dataclasses in polymarket_bot/config/settings.py for RiskConfig, StrategyConfig, and RuntimeConfig with sensible defaults and safety limits.
• Implement a mock data collector polymarket_bot/data/collector.py that returns synthetic MarketState samples and history for local development.
• Implement DecisionEngine in polymarket_bot/decision/engine.py that computes a Kelly-based size, EV, and simple gating rules based on liquidity and minimum probability.
• Implement a simulated ExecutionEngine in polymarket_bot/execution/executor.py with retry logic and a dry_run simulated fill mode, and leave a TODO for real API integration.
• Add a Kronos model adapter polymarket_bot/model/kronos_adapter.py that wraps Kronos, KronosTokenizer, and KronosPredictor to produce a heuristic probability from predicted next price.
• Add a simple TradeLogger in polymarket_bot/monitoring/logger.py that appends JSON lines with UTC timestamps to a log file.
• Add an orchestration entrypoint polymarket_bot/main.py with run_once() to wire collector, predictor, decision engine, executor, and logger into an end-to-end demo pipeline.

Testing

• No automated tests were added for this change.

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Codex Task

[client1429]

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