[Dashboard] Use secret as AP password

**Describe the problem you have/What new integration you would like**
I don't really get why we generating unique AP password for each device. With lots of devices it's kinda hard to maintain it. Why don't just add an option to use secret as AP password by default?

**Please describe your use case for this integration and alternatives you've tried:**

**Additional context**

Start by locating the dashboard configuration and the code that generates per-device AP passwords, then trace how the existing secret is stored and exposed. Done means an explicit option can use the secret as the default AP password without breaking the current per-device behavior; the issue names no files or tests.

Written by the indexing model from the issue text.