No Polling

Waiting for something by repeatedly checking whether it happened yet — expect.poll, vi.waitFor, an interval that re-reads until a value flips, a loop draining a queue on a timer — is banned everywhere in this repository: app code, server code, Azure Functions, and tests. Polling converts a completion signal we already own into a timing guess; the guess is flaky under load, wastes cycles when idle, and hides the real dependency (the code no longer says what it is waiting for, only how often it checks).

Every wait must be one of:

• An awaited promise — the operation hands back its own completion. Fire-and-forget work is still awaitable on demand: getSynchronizedFunction tracks every in-flight call and waitForSynchronizedFunctions() drains them deterministically (this is how tests assert on view-count telemetry without racing it).
• An event or callback — emitters (messageEventEmitter), tRPC subscriptions, Web PubSub, watchers. The producer tells the consumer; the consumer never asks.
• A scheduled delivery — work that must happen at a time is enqueued for that time (Service Bus scheduled messages, EventGrid) rather than discovered by a consumer loop asking "anything yet?".

Periodic work on a fixed cadence is not polling: the clicker game tick, the autosave interval, and animation timers run because time passed, not to check whether something else finished. The test is the purpose of the timer — "do the thing every N seconds" is scheduling; "check every N seconds whether the thing happened" is polling and gets rewritten around the signal that already exists.

If a dependency genuinely exposes no signal — no promise, no event, no webhook — that is an integration-design problem to fix at the boundary (add the completion handle, subscribe to the service's events), never a license to poll around it.

The mechanical surfaces are lint-enforced: expect.poll, vi.waitFor, and vi.waitUntil are no-restricted-syntax errors in the shared ESLint config. Hand-rolled check-on-a-timer loops can't be caught by a selector, so those fall to review under this standard.