fix: preserve whitespace in device hotspot SSIDs

[fython]

The device-hotspot name dialogs trimmed legal SSID whitespace: entering "CarPlayTest " saved "CarPlayTest", so the iPhone could receive credentials for a different network. First-time setup and editing an existing hotspot now preserve the SSID exactly.

Only the two SSID inputs opt into preserving whitespace. Ordinary text inputs retain trimming, passwords remain unchanged, and the existing blank-name, UTF-8 byte-length, NUL, and password validation still runs on the complete input.

Validation:

• Reproduced the whitespace loss with a failing UI test on the previous code.
• Added six UI regression tests covering setup, edits, reopening, leading/trailing spaces, UTF-8 and 32-byte limits, invalid inputs, passwords, and cancellation.
• All 478 shared/App unit tests passed; Android Lint reported no errors and the debug APK built successfully.

SSID values already trimmed by an older version must be re-entered with their complete hotspot name.

Fixes #8.