Add Ability to Mark Receive Addresses as Used Directly on Specter DIY

# Add Address Tracking / Mark Addresses as Used on Specter DIY Device

## Problem

When using Specter DIY as a receive-only signing device without direct wallet software interaction, it is easy to accidentally reuse Bitcoin addresses.

Currently, Specter DIY can derive and display receive addresses, but it does not provide a way to track which addresses have already been shared or used. This increases the risk of address reuse, especially for users who frequently generate receive addresses directly on the hardware device.

## Proposed Solution

Add a simple address management feature that allows users to mark derived receive addresses as "used" directly on the Specter DIY device.

Possible implementation:

- Display a list of recently derived receive addresses.
- Allow the user to manually mark an address as:
- Unused
- Shared
- Used
- Store the status locally on the device (SD card or internal storage).
- When generating a new receive address, visually indicate previously marked addresses.
- Optional warning when the user selects an address already marked as shared or used.

## Benefits

- Reduces accidental address reuse.
- Improves privacy for users operating primarily from the hardware device.
- Useful for air-gapped workflows.
- Helps users who do not always have access to their wallet software.
- Makes Specter DIY more practical as a standalone Bitcoin receiving device.

## Example Workflow

1. User derives a receive address on Specter DIY.
2. User shares the address with a payer.
3. User marks the address as "shared" on the device.
4. After funds arrive, the user marks it as "used" (or the status could later be automated through wallet integration).
5. Future address generation clearly distinguishes fresh addresses from previously used ones.

## Additional Ideas

- Display address usage counters per account/derivation path.
- Export/import address status data via SD card.
- Optional "Next Unused Address" shortcut.
- Optional address book/history screen showing previously generated receive addresses.

## Motivation

Many users use Specter DIY in highly air-gapped setups and may not always have wallet software available to track address usage. A lightweight address status feature on the device itself would improve privacy and usability while reducing the risk of accidental address reuse.

Start by locating the receive-address derivation and display entry points, then inspect how Specter DIY stores device-local data. Clarify the required status states and persistence behavior before implementation; done should include marking addresses, visibly distinguishing their status during later generation, and covering the described receive-only workflow.

Written by the indexing model from the issue text.