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

[client1429]

Motivation

• Provide a lightweight scaffold for an automated PolyMarket trading bot that uses the Kronos model for short-term probability inference.
• Bundle a mock data collector, a decision engine (EV + Kelly + risk caps), an execution abstraction with dry-run mode, and simple logging to accelerate integration and testing.
• Ship an orchestration entrypoint and usage instructions so the scaffold can be run locally and incrementally replaced with real integrations.

Description

• Add package polymarket_bot with a README and main.py orchestration entrypoint that wires together the components and exposes run_once().
• Add configuration dataclasses in config/settings.py for risk, strategy, and runtime parameters and default values like dry_run=True.
• Implement a mock market collector in data/collector.py, a Kronos inference adapter in model/kronos_adapter.py, a decision engine in decision/engine.py (Kelly sizing and EV check), an execution engine in execution/executor.py (dry-run and retry logic), and a simple append-only logger in monitoring/logger.py.
• Provide package __init__.py stubs for subpackages and a README with run and python -m py_compile compile-check instructions.

Testing

• Ran a basic static compile check using python -m py_compile on the new module files and it completed successfully.
• No automated unit tests were added in this change set.

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Codex Task

[client1429]

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