Initial commit: Tablet lending system with user-tablet many-to-many relationship

- Database schema: tablets, users, loans (junction table)
- CLI app: minimal_app.py
- Web apps: app.py (Flask), simple_app.py (http.server)
- Features: loan management, search, user loans view, project notes
- Git structure: CONTRIBUTING.md, .gitignore

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

CONTRIBUTING.md

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+# Contributing Guide
+
+## Git Workflow
+
+### Branch Strategy
+
+| Branch Type | Naming | Purpose |
+|-------------|--------|---------|
+| `main` | `main` | Production-ready code |
+| `develop` | `develop` | Integration branch for features |
+| Feature | `feature/<name>` | New functionality |
+| Hotfix | `hotfix/<name>` | Urgent bug fixes |
+
+### Workflow
+
+```bash
+# Clone repository
+git clone <repository-url>
+cd GestionTablets
+
+# Setup develop branch
+git checkout -b develop
+
+# Create feature branch
+git checkout -b feature/my-feature
+git push origin feature/my-feature
+
+# Make changes, commit
+git add .
+git commit -m "feat: add my feature"
+git push origin feature/my-feature
+
+# Create Pull Request to develop
+```
+
+### Commit Message Format
+
+```
+type(scope): description
+
+[optional body]
+
+[optional footer]
+```
+
+**Types**:
+- `feat`: New feature
+- `fix`: Bug fix
+- `docs`: Documentation changes
+- `refactor`: Code refactoring
+- `chore`: Maintenance tasks
+- `test`: Test-related changes
+
+**Examples**:
+- `feat(loans): add user loans view page`
+- `fix(tablet): validate serial number uniqueness`
+- `docs: update README with database schema`
+- `refactor(app): extract loan logic to service`
+
+### Pull Request Process
+
+1. Target `develop` branch (or `main` for hotfixes)
+2. Include clear description of changes
+3. Reference related issues
+4. Wait for code review
+5. Squash merge preferred
+
+### Reverting Changes
+
+```bash
+# Discard unstaged changes
+git checkout -- file.txt
+
+# Unstage file
+git reset HEAD file.txt
+
+# Revert to previous commit (safe)
+git revert HEAD
+
+# Hard reset to commit (destructive)
+git reset --hard <commit-hash>
+```