* perf(stores): defer safeStorage writes off the interaction path
Session switches funnel every persisted store slice through safeStorage.setItem,
and doing those large JSON.stringify writes synchronously blocked the main
thread for over a second. Add a write-behind buffer that:
- Defers each setItem/removeItem to a later task via setTimeout(0) so the
click-to-paint path is not blocked.
- Coalesces repeated writes to the same key into a single backing flush.
- Serves pending values from memory so read-after-write stays consistent
within the deferral window.
- Flushes synchronously on pagehide/beforeunload/visibilitychange/freeze so
deferred state survives tab close, reload, and the mobile freeze lifecycle.
Adds a test covering write deferral, coalescing, and pending read serving.
* fix(stores): defer persisted JSON serialization
* fix(stores): defer direct safeStorage writes
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Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>
