[Create/Edit Contact] Web core functionality for managing contacts

[db-ot]

User Story

As a user, I want to quickly create a new contact with basic information so I can manage my contact list easily.

Description

This ticket covers the UI for basic contact creation. The flow includes:

• A "+" button that opens the contact creation form / dialog
• Input fields: First name (optional), Last name (required), Email (optional), and Phone number (optional).
• A "Save" button to submit the form.
• On submission, data is validated and sent to the backend.
• Users receive feedback on success or failure.

This is the minimal viable contact creation feature. Extended fields, photo upload, and other features are not part of this ticket and will be handled separately.

##Value

• Delivers the core functionality for managing contacts.
• Forms the foundation for further enhancements (e.g., custom fields, photo upload)
• Provides a familiar, mobile-like user experience for fast and easy contact entry.

##Acceptance Criteria

By clicking "+" opens the contact form.
- The form includes:
   - First name (optional)
   - Last name (required)
   - Email (optional, must be valid format)
   - Phone number (optional)

By clicking "Save":
   - Validates inputs ( required there?
   - Sends data to backend
   - Shows success message on success
   - Shows error message on failure
- UI is responsive and keyboard accessible

##Mockup

suggestion for later

[db-ot]

Edit is the follow up from create. Existing contacts could be edited and the changes are done by the save button.