Adds InterpOp::SetDisplayName (legacy log 0, always-on global topic —
same propagation as Author/Revoke), materialised as
StateEvent::DisplayNameSet and exposed as ZodiaClient::set_display_name.
Receivers persist the newest name per peer (last-writer-wins by the
op's own timestamp, not local receipt time, since local time would let
a replayed stale op incorrectly "win"). The GTK app resolves a shown
name as: local nickname > peer's broadcast name > truncated hex,
threaded through every place a peer's name was previously
hex-only. A pencil button next to the Network tab's status line lets
the user set their own name, persisted via a new display_name.txt in
LocalConfig and re-broadcast on every reconnect.
Also tags every zodia-sdk cucumber test peer with a reserved sentinel
name (zodia_sdk::TEST_PEER_DISPLAY_NAME) and has the app filter any
peer broadcasting it out of the Network tab's discoverable-peers list —
mDNS reaches the whole LAN, so a local test run was showing up as
"new people" in a real running instance on the same network. A local
nickname still overrides the filter, for a developer who wants to keep
a specific test peer visible.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
