Working section beta toggle on desktop does not carry over to the iPhone app #19094

What happened

The user enabled the beta Working section in the desktop app and expected the same collapsible Working section in the iPhone app's thread list. It did not appear there. In their words:

why is there not also a collapsable working section in the iphone app as in the desktop app? even if this is still in beta?

i would argue on iphone it is more important because screen space is scarce

nevermind i found it and it worked. the problem was that the setting was not synced correctly.

The user found a separate "Working section" toggle in the iPhone app's settings, turned it on, and the section appeared. From their side this looked like a setting that failed to sync.

Diagnosis

Nothing failed: the two clients store this toggle separately and the mobile app does not sync client settings at all, so this is a feature request rather than a bug.

• Desktop/web reads the client setting sidebarWorkingShelfEnabled (packages/contracts/src/settings.ts:472, default false), used in apps/web/src/components/Sidebar.tsx:2431.
• Mobile reads a device-local preference workingShelfEnabled, documented as "Device-local counterpart of web's sidebarWorkingShelfEnabled beta" (apps/mobile/src/persistence/mobile-preferences.ts:84).
• The mobile settings screen states the limitation in a comment: "Mobile has no client-settings sync" (apps/mobile/src/features/settings/SettingsThreadsRouteScreen.tsx:293).
• The same applies to other mirrored toggles in mobile-preferences.ts, such as planModeEnabled and followUpBehavior.

Nothing in either client tells the user the toggle is per-device, so enabling a beta on one device and not seeing it on the other reads as a broken sync.

Requested, in order of preference:

1. Sync these mirrored client settings between desktop/web and mobile.
2. Failing that, note in the mobile and desktop settings UI that the toggle applies to this device only.

File and line references are from commit 511d20c, the tag of the installed version.

Steps to reproduce

1. In the desktop app, enable the beta Working section in Settings.
2. Confirm working and monitoring threads fold into a Working section in the sidebar.
3. Open the iPhone app connected to the same server.
4. Observe: the thread list has no Working section.
5. In the iPhone app's thread settings, under Beta, turn on "Working section".
6. Observe: the Working section now appears.

Version

0.0.46-nightly.20261012.3035 (commit 511d20c); iPhone app 2.0 via TestFlight

Environment

Server on Linux x64 (7.2.5-3-omarchy), Node 24.21.0; iPhone app 2.0 (TestFlight)

Evidence

apps/mobile/src/persistence/mobile-preferences.ts:84
  /** Device-local counterpart of web's `sidebarWorkingShelfEnabled` beta. */
  readonly workingShelfEnabled?: boolean;

apps/mobile/src/features/settings/SettingsThreadsRouteScreen.tsx:292
  * Device-local legacy toggles. Mobile has no client-settings sync, so this is
  * the counterpart of web's Settings → General → Legacy features backed by
  * mobile preferences.

Related issues

None found. Searched "mobile settings sync", "sync client settings mobile", "working section mobile" and "working shelf".

Fix applied or workaround

None on the machine. The user enabled the "Working section" toggle in the iPhone app's own settings, which resolved it for them.

Filed by

claude (claude-opus-5-5) via t3 triage