live — never wait on the network to paint

a world opens on what it already knows. a fetch runs in the background. the neuron can leave before the answer arrives. the surface never blanks, never says "loading", never holds the frame for a socket.

this is the same lesson as hung GETs freezing every chain: a slow neighbour may only stall its own thread. here it is a law of the shell, not just of probes.

the rule

1. paint last known — a number, a table, a graph, a page. zero is a number. an empty page is a page. "querying…" is a lock.
2. fetch off the frame — another thread, a timeout, one in-flight at a time. the UI thread never calls out.
3. tabs always work — entering a world does not own the input. leaving cancels nothing the user can see; the request may finish in the dark and the next visit shows it.
4. errors are receipts, not curtains — a failed fetch writes a dim line under the last good value. it does not replace the value with the error.

sigma's balance is the first instance: cached ~/cyb/sigma-chain.json on the way in, a silent /balance behind it. oracle's block list, body's network rows, soma's answer stream follow the same shape.

see cy/specs/sigma, cy/specs/state (T3 never pretends to be proof), body's networks.rs (timeouts, one thread per chain).