banter::BanterLabResources

GUI-thread-safe locator for the live BanterLab widgets.

Detailed description

Each accessor walks `qApp->activeWindow()` for a `BanterLabActivity` child via `findChild`. When BanterLab has never been opened (lazy activity not yet instantiated), the accessors return nullptr and OTs fail with the message produced by `notOpenMessage()`.

The accessors are safe to call from worker threads — the underlying widget lookups marshal onto the GUI thread via `opal::guiCall`.