fix(sequences): land the owned frame-provider StrictMode fix on main

[vutuanlinh2k2]

Re-lands the frame-provider StrictMode lifecycle fix from #60, which was merged into the now-deleted stacked base branch (linh/fix/playback-clock-strictmode-dispose) instead of main, so its change never reached main. #59 (the clock fix) did land. This PR cherry-picks that commit onto main.

Identical to the already-reviewed #60 diff (provider block + two StrictMode tests); no new changes. See #60 for the full rationale.

pnpm typecheck ✅ · pnpm test ✅ (1221 passed) · pnpm build ✅

[tangletools]

✅ Auto-approved PR — d583dfa3

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_{tangletools · auto-approval · reason: blanket_auto_approve · 2026-06-15T08:52:49Z}