Measuring
Startup

Where each is recorded:

• Server start (src/node/app/app.ts): startServer opens chord.app.start with the app's telemetry context (the telemetry option) and passes the span's context to each step: the layout, the store, the workers components (each builds its worker base: chord.base.build worker:<kind>), the surfaces (web, tui), the server scan (server), the plugins component (discovery, builds, evaluation), host.load (its existing chord.load gets this parent), the listener.
• Worker start (src/node/workers/, src/node/app/worker.ts): the server's chord.resolve puts its carrier into the start message; the worker's recorder opens chord.worker.start linked to it and records the fork (the time from the process's own start, performance.timeOrigin, to the entry's first line), the lock, its store, the connect, each script's evaluation and the load; the worker sends them to the server as it sends all its spans.
• Page start (src/web/page.ts): a page that records (startPage({ telemetry: true })) opens chord.page.start when its base bundle runs, with the time from navigation start (performance.timeOrigin) as an attribute, then the connect, each plugin script's evaluation and the load.
• Apply (app.applyChanges): chord.app.apply with discovery (when the set changed), each build, and each rollout step; each host's chord.reload as today under its step (workers' under their own trace, linked).

const app = await startServer(options, context);
console.log(app.startup.line);   // "started in 1,840 ms: bases 914 (web 610, worker:session 240, server 64), plugins 410, load 180"
app.startup.steps;               // [{ name: "chord.base.build", attributes: { artifact: "web" }, ms: 610 }, …]

app.startup is recorded by the same code that opens the spans, from one clock read at each step's start and end; without a telemetry store the steps are still timed (a start is one call; the cost is a few performance.now() reads). The worker and the page have no summary: their spans are in the store, read with the kit's trace tools (trace.ts as in the tutorial; later a viewer plugin).

• The schema entries in CHORD_TELEMETRY_SCHEMA (version bumped), each span recorded where listed, its parent and attributes checked with the in-memory telemetry adapter: a server start with workers and both surfaces; a worker start linked to its resolve; a page start in the browser; an Apply with a failed plugin and a stopped rollout.
• app.startup with and without a telemetry store; its line.
• Without an adapter: no new spans, the existing cost guards unchanged.
• Design §29 (the tiers and the new roots), the kit README (startup), the plugins, surfaces and workers READMEs; the tutorial's trace chapter shows a start's trace.
• npm run check, the touched suites.