Chore/add precommit config

[mehmetyavuzz43]

Adds a pre-commit configuration using Ruff and Black, enabling automatic code formatting and linting on commit.

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[!NOTE] Introduces basic repo tooling for formatting/linting and environment checks.

• Adds .pre-commit-config.yaml with ruff (auto-fix) and black hooks
• Adds scripts/bash/check_env.sh to verify .env exists and required vars (POLYGON_WALLET_PRIVATE_KEY, OPENAI_API_KEY) are non-empty

^{Written by Cursor Bugbot for commit 3444c59edb83b4cb6c51943eac2b030244b4d0ad. This will update automatically on new commits. Configure here.}