Problem

When adding a new miner, it is not possible to fetch the max hash rate and max power values from the device. The "fetch from miner" buttons next to the Max Hash Rate and Max Power fields (and the Model/Name fields) are only shown when editing an already-saved miner, because the underlying endpoints operate on a persisted miner (/miners/{id}/limits, /miners/{id}/info). The user is therefore forced to type these values manually during creation, or to save the miner and re-open it in edit mode to retrieve them.

Proposed solution

Allow retrieving device data (max hash rate, max power, and model/hostname) directly from the associated controller during miner creation, without requiring the miner to be saved first.

Scope:

• Provide controller-level read endpoints to query a controller directly (no persisted miner required), following the existing pattern used to read live miner details from a controller.
• In the miner form, enable the "fetch from miner" buttons for Max Hash Rate, Max Power and Model also in creation mode, using the selected controller(s).
• When the selected controller provides the relevant detection capability, populate the corresponding field with the fetched value and highlight it.

Acceptance criteria

• In the "Add Miner" form, with at least one controller selected, the user can fetch Max Hash Rate and Max Power from the device.
• The Model (and name/hostname) can likewise be fetched from the device during creation.
• Fetched values populate and visually highlight the corresponding fields, without requiring the miner to be saved first.
• If a selected controller does not provide a capability, the action fails gracefully with a readable message.