Add catch-dotenv hook and corresponding tests to manage .env files

[rwbot]

This pull request introduces a new pre-commit hook to block .env files from being committed to the repository and optionally generate a sanitized .env.example file. It also ensures .env is added to .gitignore automatically, helping prevent accidental exposure of secrets. The hook is registered in the project configuration and includes a comprehensive test .env file for validation.

New pre-commit hook for dotenv protection:

• Added a catch-dotenv hook to .pre-commit-hooks.yaml that blocks commits containing .env files and can generate a value-sanitized .env.example file.
• Implemented the pre_commit_hooks/catch_dotenv.py script, which blocks .env file commits, updates .gitignore with a canonical banner and .env entry, and generates .env.example with only variable names.
• Registered the new hook as a console script in setup.cfg for CLI use.

Testing resources:

• Added a sample testing/resources/test.env file with dummy secrets and various environment variables for testing the hook’s behavior.

[Copilot]

Pull Request Overview

This PR introduces a new pre-commit hook called catch-dotenv that prevents committing .env files to version control, helping protect secrets from accidental exposure. The hook automatically adds .env to .gitignore and can optionally generate a sanitized .env.example file with variable names but no values.

Key changes:

• Implemented the catch-dotenv hook with atomic file operations and gitignore normalization
• Added comprehensive test suite covering edge cases, concurrency, and error scenarios
• Created a test resource file with realistic environment variable examples for validation

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pre_commit_hooks/catch_dotenv.py	Core hook implementation with gitignore management and example file generation
tests/catch_dotenv_test.py	Comprehensive test suite covering functionality and edge cases
testing/resources/test.env	Test resource file with dummy environment variables for validation
setup.cfg	Added console script entry point for the new hook
.pre-commit-hooks.yaml	Registered the new hook configuration
README.md	Added documentation for the catch-dotenv hook

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