track: Code coverage reporting implementation

## Overview
Track the implementation and improvement of code coverage reporting for all hook scripts.

## Current Status
- ✅ Coverage workflow created (`.github/workflows/coverage.yml`)
- ✅ kcov integration configured
- ⚠️ Coverage currently at 0% (no hooks passing tests)

## Goals
- [ ] Fix hook scripts to pass shellcheck
- [ ] Achieve 50% coverage
- [ ] Achieve 80% coverage target
- [ ] Add coverage badge to README
- [ ] Integrate coverage checks in PR reviews

## Tracking Metrics
- Current coverage: 0%
- Target coverage: 80%
- Number of hooks tested: 3/26
- Number of test files: 6

## Related PRs
- Initial coverage setup: (this commit)

## Dependencies
- Depends on #27 (test coverage for all hooks)
- Blocks v1.0.0 release

## Action Items
1. Fix shellcheck errors in hook scripts
2. Update tests to handle hook script issues
3. Add coverage badge to README
4. Configure coverage as required PR check

## Milestone
Test Coverage 80%

Commencez par examiner .github/workflows/coverage.yml, les 6 fichiers de test existants et l’issue de dépendance #27. Vérifiez les 26 scripts de hooks et la couverture de tests actuelle de 3/26, puis traitez les problèmes de shellcheck et de tests indiqués. Le travail est terminé lorsque les objectifs de couverture indiqués sont atteints, qu’un badge est ajouté au README et que la couverture est configurée comme vérification obligatoire des PR.

Rédigé par le modèle d'indexation à partir du texte de l'issue.