Spec from the mobile side, v2. One endpoint (POST /api/sendoff/send — the one
sanctioned door into another user's filesystem, sender identity from the token),
a push category whose route deep-links the Files apps, and a minimal devices
registry for the send-to pickers. The mobile half is already shipped against
this and degrades silently until it exists.
Lives here rather than in COMMS because it is a spec to implement, not a
message: the repo is where it can be corrected as the implementation teaches.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
