iOS can now send a document from Files. This build treated `file` as a kind
from a newer peer: legible, because a file envelope always carries a
caption naming the document, but only as text.
The engine now knows the kind, parses the additive `fn`/`cls`/`cmp` keys,
and can assemble them — so sending works in both directions, not one.
🔴 The interop test parses an envelope produced by the iOS build rather
than by this engine. Two implementations of one format that each only test
against themselves agree right up to the day somebody sends a real file,
and the symptom is "[unsupported attachment]" with no clue why. It also
pins the two rules that keep older peers working: a file envelope is never
captionless, and a photo envelope still carries none of the new keys.
⚠️ The bubble shows the classification as a MARKING. It says how the
sender had it filed; it does not mean this device was cleared for it, and
whoever can read the message already has the key.
⚠️ No "Save to Files" on this side yet — this build has no Files of its
own, so the button would be one that cannot work. Showing what arrived is
the honest half of parity while the other half is built.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
