Hide native browser tabs while plugin dialogs are open

[ariofrio]

Human comments

What was wrong

A Browser tab's native view paints above all renderer DOM, so bb hides it while useIsBrowserDimmingModalOpen() is true. Only host overlays raise that counter: the app build swaps in the real useBrowserDimmingModal, but plugins vendor the registry's no-op flavor, so a plugin Dialog never hides the view and sits under the page. Reported in #3812; this implements the host-side observer VKirill proposed there on 2026-09-23.

What changed

useIsBrowserDimmingModalOpen in apps/app/src/hooks/useBrowserDimmingModal.ts now also reports true while an open plugin dialog portal ([data-bb-plugin-root][data-bb-portaled-overlay][role="dialog"][data-state="open"]) is in the document. One shared MutationObserver, read through useSyncExternalStore, tracks those portals, and notifies subscribers only for mutations that touch a plugin portal. The existing browser-view coordinator does the hiding and restoring. Already-shipped plugins benefit without a rebuild, and the host counter is unchanged. No wire, CLI, or SDK change.

Deviation from the proposal in #3812: this matches only plugin-rooted, portaled dialogs, not every role="dialog", menu, or listbox, and adds no data-bb-browser-dimming marker. That keeps host menus and any unrelated DOM from toggling the view. Plugin menus still overlap the page; an SDK hook would be the better route for those.

How you verified

A new plugin-dialog case in apps/app/src/components/ui/dialog.browser-dimming.test.tsx failed before the change and passes after. pnpm exec turbo run test --filter=@bb/app -- --run src/components/ui/dialog.browser-dimming.test.tsx, pnpm exec turbo run typecheck --filter=@bb/app, and oxfmt --check pass. Motivating plugin: Ribbon's dialogs, e.g. the action editor in ariofrio/ribbon#121.

Fixes #3812

_{Written by Claude and Codex}

🤖 Generated with Claude Code

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[github-actions]

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