iOS WebKit: gantt-layout-loader throws on missing window.requestIdleCallback — global error boundary on every issues-list view

Description

Plane CE's lazy-loaded gantt-layout-loader chunk calls window.requestIdleCallback without feature detection or a polyfill. iOS WebKit (Safari, iOS Chrome, iOS Firefox — all WebKit-backed under Apple's App Store rules) has never implemented requestIdleCallback — open WebKit gap since 2016 (webkit.org#164193). The throw propagates up, React's error boundary catches it, and the user sees the generic "Looks like something went wrong" page on every issues-list / project view.

Steps to reproduce

1. iPad (any iOS / iPadOS version), Chrome (CriOS user-agent — but iOS Safari and iOS Firefox would all fail the same way; see "Why the matrix is weird" below).
2. Sign in to a Plane CE instance.
3. Navigate to any project's /projects/<uuid>/issues/ page.
4. The full error boundary fires.

Console error (from Safari Web Inspector against the iPad)

TypeError: window.requestIdleCallback is not a function.
(In 'window.requestIdleCallback(()=>{h.current&&(S.current=`${h.current.offsetHeight}px`)})', 'window.requestIdleCallback' is undefined)
— gantt-layout-loader-BH8Iumhn.js:1:5524

React Router caught the following error during render
— componentDidCatch (chunk-EPOLDU6W-PsE1YSAx.js:4:2496)

[also] Minified React error #418 (hydration failed) and #423 (client-side recovery also failed)
— both downstream of the same throw.

Why the matrix is weird (and the cause is clear)

So the bug has been sitting hidden behind a UA-sniffing branch that only one of three iOS browser paths exercises.

Suggested fix

Either:

A — Polyfill requestIdleCallback once at app entry:

if (typeof window.requestIdleCallback !== 'function') {
  window.requestIdleCallback = (cb) => {
    const start = Date.now();
    return setTimeout(() => cb({
      didTimeout: false,
      timeRemaining: () => Math.max(0, 50 - (Date.now() - start)),
    }), 1);
  };
  window.cancelIdleCallback = (id) => clearTimeout(id);
}

B — Feature-detect inside gantt-layout-loader and fall back to setTimeout(fn, 0) for the height-measurement use case (which doesn't actually need idle-time semantics; it's just deferring a layout measurement).

Either is a few lines. (A) catches every other requestIdleCallback use in the codebase.

Environment

• Plane CE v1.3.1 (self-hosted, full upstream image set)
• Client: iPad (any), Chrome on iOS / iOS WebKit

Locate the source for the lazy-loaded gantt-layout-loader and the application entry point, then reproduce the failure on an iOS WebKit browser using the project's issues-list or project view. Choose the fallback approach that fits the existing structure; done means the view renders without the global error boundary when requestIdleCallback is unavailable.