Two causes. The connect step had no timeout, so an unreachable device was
retried indefinitely instead of falling through to hold-for-later; it now
gives up after 15s and holds the offer as designed.
The picker also waited on the whole exchange, which includes a person on the
other device deciding — up to two minutes. It now closes on tap and reports
the outcome as a message, and a decline or an unanswered offer is shown as
information rather than an error, since the offer did arrive.
Send to a device now sits alongside the QR code, NFC, and export actions,
since an offer is another way to deliver the same invitation. Picking a
device pushes the existing transfer rather than re-sharing the files.
The picker lists only devices holding a live grant, so nothing offered there
can fail on tap, and it distinguishes accepted from waiting for that device
to open the app.
Also fixes the deprecated SF Symbol and the two Sendable warnings introduced
with the contacts screen: the sections now talk to the model directly rather
than storing view callbacks that a Binding setter has to convert.
