Devices - redesign admin UI

[AmaLuci]

Goal
Provide a clear and centralized overview of all devices (physical phones), simplifying provisioning and model management.

This section includes:

• Devices list (provisioned phones overview, status, main info)
• Device assignment to users
• Provisioning status and actions
• Supported models management
• Add / edit device flows

Design goals

• provide a clear overview of all provisioned devices
• simplify device provisioning and assignment to users
• make device status and configuration immediately understandable
• clarify the relationship between devices, users and supported models
• reduce errors in provisioning and model selection
• ensure scalability for installations with many devices

Output
hi-fi mockups
main interaction flows (e.g. add device, assign to user, provisioning)
states and edge cases where relevant