[Feature] Assign IP addresses to non-headscale devices

[crimewaffle]

Use case

Currently, when accessing multiple networks with identical subnets (e.g., 10.10.10.0/24), only one network can be routed at a time. Switching between these networks requires manually disabling one subnet route and enabling another, which is inefficient.

Description

Introduce the ability to assign unique Headscale IPs (100.64.0.0/10) to specific devices, bypassing the need to route entire subnets. This would allow direct access to individual devices across multiple networks without conflicting subnet routes.

Example Use Case:

Network1: 10.10.10.0/24 (Switch/AP at 10.10.10.11)
Network2: 10.10.10.0/24 (Another Switch/AP at 10.10.10.175)

With this feature, users could assign a unique Headscale IP (e.g., 100.64.x.x) to the switch at 10.10.10.11 on Network1 and another Headscale IP to the switch at 10.10.10.175 on Network2. This eliminates the need for manual routing of entire subnets and simplifies access to specific devices on overlapping subnets.

Contribution

• [X] I can write the design doc for this feature
• [ ] I can contribute this feature

How can it be implemented?

No response