Write BLE / bridge / hook troubleshooting guide

[TheNorthStarYang]

Goal

Create a troubleshooting guide for BLE, bridge, and hook-related issues in AhaKey Desktop.

Scope

• explain what BLE bridge is for
• explain what hook installer is for
• provide a simple troubleshooting order
• avoid unrelated refactors

Where to edit

• repository: desktop
• relevant path: docs/debug-ble-bridge-hook.md

Notes

This issue is part of the early community onboarding / baseline cleanup.

Contributors are welcome.