feat(non-loanable-devices): implement non-loanable device management

- Add non_loanable_devices table to database schema
- Add web interface routes: /non_loanable_devices, /add_non_loanable_device, /edit_non_loanable_device, /delete_non_loanable_device
- Add CLI menu options 8-10 for non-loanable device management
- Add templates for non-loanable device CRUD operations
- Update README.md with new feature documentation
- Update REQUIREMENTS.md marking non-loanable devices as implemented
- Add gestiontablets.sh script

Implements: #porDefinir Registrar nuevos dispositivos no prestables

README.md

@@ -10,15 +10,16 @@ A simple SQLite-based system for managing tablet lending and returns.
 - **Return Management**: Record when tablets are returned
 - **History Tracking**: Complete history of all loans and returns
 - **User Loans View**: See all tablets loaned to each user (demonstrates one-to-many relationship)
+- **Non-Loanable Devices**: Track inventory devices that cannot be loaned (e.g., projectors, monitors)
 - **Project Notes**: Markdown editor for development documentation
 
 ## Files
 
-- `minimal_app.py` - Interactive command-line application
+- `minimal_app.py` - Interactive command-line application (includes non-loanable device management)
 - `test_app.py` - Test script that demonstrates functionality
-- `tablets.db` - SQLite database (created automatically)
-- `simple_app.py` - Web-based version (requires Flask)
-- `app.py` - Alternative web version (requires Flask)
+- `tablets.db` - SQLite database (created automatically, includes non_loanable_devices table)
+- `simple_app.py` - Web-based version (requires Flask, includes non-loanable device management)
+- `app.py` - Alternative web version (requires Flask, includes non-loanable device management)
 
 ## Quick Start
 
@@ -144,6 +145,7 @@ python3 app.py
 - **Loan Tablet**: Loan a tablet to a user (with search for large datasets)
 - **User Loans**: View all tablets loaned to each user - demonstrates the **one-to-many relationship** (one user, multiple tablets)
 - **Loan History**: Complete history of all loan and return transactions
+- **Non-Loanable Devices**: Manage inventory of devices that cannot be loaned (add, edit, delete, view)
 - **Project Management**: Markdown editor for development notes (saved to `notes_development/project_notes.md`)
 
 ## Database Backup