console: duplicate React keys during app-shell boot — 'Encountered two children with the same key'

[os-zhuang]

Found while browser-verifying #2927 (PR #2930). Pre-existing and unrelated to that change — filed rather than left buried, per AGENTS.md #10.

Symptom

A hard load of any console route logs React's duplicate-key error, four times:

Encountered two children with the same key, `%s`. Keys should be unique so that
components maintain their identity across updates. Non-unique keys may cause
children to be duplicated and/or omitted — the behavior is unsupported and
could change in a future version.

This is an error, not a warning, and React is explicit that the resulting behaviour is unsupported: siblings sharing a key can be duplicated or omitted, and state can attach to the wrong sibling.

Repro

1. Backend on any port (pnpm --filter @objectstack/example-showcase dev -- --fresh -p <port> in framework).
2. DEV_PROXY_TARGET=http://localhost:<port> pnpm --filter @object-ui/console dev.
3. Sign in, hard-load /system/approvals, read the browser console.

What has already been ruled out

• Not from ApprovalsInboxPage. It reproduces identically with that file swapped back to its main version, and both of its filter dropdowns (processOptions / objectOptions, the only index-free .map keys on the page) are Set-deduped by construction.
• Not from a route re-mount. Hooking console.error and then SPA-navigating away from and back to /system/approvals produces zero warnings. It fires only on the initial full page load, which points at the app-shell bootstrap (nav / sidebar / topbar rendering before data settles) rather than at any one page.

Suggested next step

Hook console.error before React mounts (e.g. at the top of main.tsx behind a dev flag) so the owner component name in the error's trailing argument is captured, rather than truncated as it is in devtools. That should name the offending .map directly.

Refs #2927, #2930.

[os-zhuang]

Closing as not reproducible.

What was tested

The duplicate-key error does not fire even once during app-shell boot — on current main (9b773f976) or on b0760501a (#2930), the commit this was filed against.

Axis	Coverage
Commit	9b773f976 (main) / b0760501a (#2930)
Backend	own --fresh app-showcase, and a long-lived persistent app-showcase DB
Console wiring	VITE_SERVER_URL= + dev proxy, and the default .env.development direct-to-:3000 (the setup in the report)
Locale	en-US / zh-CN
Viewport	desktop 1440 / mobile 390
Routes	/system/approvals, /home, /apps/{showcase_app,setup,account,crm_enterprise}, /studio, /ai, object lists, metadata, /organizations, /docs, system + developer pages — hard loads and SPA back/forward
Interactions	⌘K command palette, ? shortcuts dialog, sidebar collapse / mobile drawer

The detector itself is known-good: planting one pair of same-key siblings in ConsoleLayout produced 6 of these errors on a single boot, captured by the same listener that reports zero for the unmodified tree.

Also ruled out along the way:

• No duplicate id in any app's navigation tree (58 / 51 / 10 / 19 items across the four apps).
• No duplicate name or id across object / view / app / dashboard / page / report metadata.
• All ten locale packs have three distinct console.loadingSteps strings (LoadingScreen keys by the translated string).
• b0760501a..HEAD touches exactly one key= line in app-shell / layout / components / console (an addition in select.tsx) — so this was not incidentally fixed in between.

Correction to the suggested next step

Capturing "the owner component name in the error's trailing argument" will not work: React 19 logs this error with no component stack, only two arguments —

Encountered two children with the same key, `%s`. …
dupkey-probe

The actionable signal is the second argument — the duplicated key value (dupkey-probe above), which points straight at the offending .map.

If it comes back

Temporarily prepend this to apps/console/src/main.tsx and reload:

const _e = console.error;
console.error = (...a: any[]) => {
  if (typeof a[0] === 'string' && a[0].includes('same key')) _e('[dupkey]', a[1]);
  _e(...a);
};

Reopen with the printed key value and it can be fixed directly.