The FE connected realtime via Phoenix Channels (wss .../socket/v2), but the
Go backend serves no Phoenix endpoint — its realtime is SSE at
/v1/base/realtime (envelope {event,chain,data}). Result: repeating ws 404 ->
'Live updates temporarily delayed'.
lib/socket/sse.ts reimplements the slice of the Phoenix Socket/Channel API the
27 realtime consumers use, backed by one EventSource, behind the existing
SocketProvider/useSocketChannel/useSocketMessage seam — no consumer changes.
Envelope routes via an optional topic field or a hub-channel translation table
(blocks -> blocks:new_block/new_block today). CT harness becomes a tiny SSE
server with the same signatures. 12 vitest cases cover it.
Frontend-only; chain/indexer untouched. Data freshness remains gated on the
separate C-Chain-rollback/indexer-reorg owner items.
zeekay
507a7da852