chore: add husky pre-commit hook and configure lint-staged for code formatting

[sonmessia]

Proposed changes

Add husky pre-commit hook
Types of changes

• 🐛 Bug fix (non-breaking change which fixes an issue)

• ✨ Feature (non-breaking change which adds functionality)

• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)

• 📝 Docs (documentation only changes)

• ♻️ Refactor (code improvement without changing functionality)

Checklist

• Docker build successful (src/backend)

• All tests passing (pytest)

• Code follows project standards (Black, Ruff, MyPy)

• Service boundaries maintained

• .env.example updated (if environment variables changed)

• No debug print statements left

[Copilot]

Pull request overview

This PR adds Husky pre-commit hooks and configures lint-staged to automatically format code before commits. It sets up automated code quality checks for both the Python backend (using Black and Ruff) and the TypeScript/JavaScript frontend (using ESLint).

Key changes:

• Adds Husky v9 and lint-staged v15 as development dependencies
• Configures lint-staged to run Black and Ruff on Python files, and ESLint on frontend files
• Creates a pre-commit hook that triggers lint-staged

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
package.json	Defines root-level dependencies for Husky and lint-staged, and configures lint-staged patterns for backend and frontend files
package-lock.json	Lockfile with all dependency versions and integrity hashes for Husky, lint-staged, and their transitive dependencies
.husky/pre-commit	Pre-commit hook script that executes lint-staged on staged files

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[Copilot]

The bash command for ESLint will not work correctly. When lint-staged passes file paths to this command, they will be passed as arguments (e.g., bash -c '...' arg1 arg2 arg3), but ${0} refers to the script name/path, not the arguments.

Additionally, since the command changes directory to src/frontend but receives file paths relative to the repository root (e.g., src/frontend/src/App.tsx), the paths won't resolve correctly.

Recommended fix - replace line 17 with:

"eslint --fix"

This will work because lint-staged will execute this command from within src/frontend directory when the glob pattern matches, and eslint will receive the correct relative file paths.

Suggested change

	"bash -c 'cd src/frontend && npx eslint --fix ${0}'"
	"eslint --fix"