v1.2.5 — a stuck host can no longer freeze the panel

Four fixes on paths a normal session takes. The catalogue read and the panel's request now have timeouts, so a router that accepts the connection but never answers turns into a readable error instead of a panel where every button is dead until a reload (start keeps a longer ceiling: it waits out the supervisor's 25s grace period). Requests queue instead of being dropped, so a click that lands during a probe poll is actually sent. Ranking reads are serialised — the vendored database handle is a module-level singleton, and two overlapping reads used to swap the connection out from under each other, swallowing the failure and making the ranking vanish for a turn. Probe polls ask for a lean payload and the client merges back the scores it already has: 49.7 KB instead of 134.9 KB per poll, and an unchanged payload no longer rebuilds the tree. Also fixes the row switch, which reported aria-pressed on a role=switch (and painted its knob from that attribute), and removes a dead sizeLabel that was computed incorrectly and never read.