About page uptime counter runs one second ahead #1643

The uptime counter on the About page runs one second ahead. TimeValue increments its counter and then formats counter + 1, adding the second twice. On the first tick the display jumps from the starting value straight to start + 2, then advances one second per tick from there. Every later value is one second too high. This affects both the core API uptime and the gateway uptime.

Where

apps/web/src/routes/_app/about.tsx:92-95:

useInterval(() => {
  valueRef.current = valueRef.current + 1;
  setState(format(valueRef.current + 1));
}, 1000);

Reproduce

1. Open the About page while the setup state reports an uptime of 5 seconds.
2. Watch the counter.

Actual: 00:00:05, then 00:00:07, 00:00:08, 00:00:09 (it skips 6). After 3 seconds it shows 00:00:09.
Expected: 00:00:05, 00:00:06, 00:00:07, 00:00:08.

Tests

apps/web/src/__tests__/about-route.test.tsx: it.fails('should show the starting uptime plus the seconds elapsed since the page opened'), with a "Known defect" comment above it. Drop .fails and the comment once fixed. should advance the uptime by exactly one second per tick, ... already passes and should keep passing.

Suggested fix

Format the incremented value directly: setState(format(valueRef.current)).

Found while raising unit test coverage in #1632.