chore: add pre-commit githooks and update gitignore

[aritro2002]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

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Description

Adds pre-commit git hooks and updates .gitignore to improve developer experience and code hygiene.

• Added .githooks/commit-msg with the following pre-commit checks:
  • ReScript formatting via npm run re:format
  • Trailing whitespace detection in src/
  • Conventional commit message validation (feat, fix, chore, refactor, docs, test, style, enhancement, ci, revert)
  • Secret scanning via gitleaks (auto-installs via Homebrew if not found)
• Added setup:hooks script to configure core.hooksPath and set correct file permissions
• Added postinstall to auto-run setup:hooks after npm install
• Added pre-commit script for manual hook invocation
• Added husky as a devDependency for git hook integration
• Updated .gitignore to cover build outputs, editor configs, logs, env files, OS artifacts, and AI agent directories (.claude/, .cursor/, .copilot/, etc.)

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How did you test it?

• Manually triggered npm run pre-commit to verify each check runs correctly
• Tested commit message rejection with a non-conventional message
• Verified formatting check runs and passes on clean ReScript files
• Confirmed hooks are applied automatically after npm install via postinstall

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Usage Notes

• No breaking changes. No API changes.
• New contributors will have hooks set up automatically after npm install
• gitleaks will be auto-installed via Homebrew on macOS if not already present

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Version Update

• I have bumped the package version in package.json following semantic versioning:
  • x.x.x for major changes (breaking).
  • x.x.x for minor changes (new feature, no breaking changes).
  • 2.1.1 for patch changes (bug fixes, minor improvements).

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Checklist

• I ran npm run re:build and verified the build artifacts.
• I reviewed the code for style, readability, and consistency.
• I verified the changes are backward compatible (if applicable).
• I tested this change in a real or simulated consuming project.
• I updated documentation, README, or usage examples if necessary.

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Screenshots or Logs