BUG | Rainbow Layouts (Chrome) | Active state is not synced for multiple tabs under the same domain

[sm17p]

Context: When multiple tabs are open for the same domain, the rainbow layout toggle state on one tab is not propagated to the others.

Refined: Sync the "rainbow layout" (and similar) preference across tabs for the same origin (e.g. via storage or broadcast).

[sm17p]

Triage pass complete.

Proposed direction:

• Treat rainbow toggle as origin-scoped state in extension storage and broadcast updates across tabs.
• Use storage.onChanged (and optional runtime.sendMessage) to immediately fan out changes.

Research notes:

• Multi-tab desync usually comes from tab-local in-memory toggles not rehydrated from shared storage.
• Origin-keyed state map avoids cross-site bleed.

Implementation slice:

1. Centralize read/write via one state service.
2. Subscribe content scripts to storage changes.
3. Add e2e covering two tabs on same origin.

Definition of done:

• Toggling rainbow in one tab updates other tabs on same origin without reload.