fix(updater): honor Later reminder cooldown

[beruro]

Problem

Choosing Later only hid the transient install prompt. The next automatic update trigger—startup, interval, foreground, online recovery, or retry—would prepare the already-downloaded update and unconditionally make the prompt visible again.

There was durable state for Skip this version, but no durable, version-scoped state for postponing a reminder.

Solution

• Persist a per-version reminder deadline for 24 hours when the user chooses Later.
• Make every automatic update path respect the active reminder deadline.
• Keep explicit install actions authoritative so a user can reopen the prompt during the cooldown.
• Remove expired or malformed reminder state before making the next prompt decision.
• Ensure a reminder for an older version never suppresses a newer release.
• Clear the current version's reminder when the user skips or installs it.
• Document the updater state ownership and reminder policy.

The resulting invariant is: automatic preparation may show the install prompt only when the current version has no active reminder deadline.

Potential risks

• The cooldown uses the system wall clock. A large manual clock change can shorten or extend the effective reminder period.
• The reminder is stored in localStorage. If localStorage is externally cleared, ORGII will remind again on the next automatic update trigger.
• A user could postpone installation while an important update is available; the cooldown is intentionally limited to 24 hours, and a newer version bypasses the old reminder.
• Real updater installation and relaunch were not exercised because they would terminate/restart the running app. Those paths were not changed by this PR.

Audit

Architecture audit covered all 10 layers. Compilation, call-path ownership, naming, default-branch exhaustiveness, persisted JSON shape, production/test entry parity, and resolver symmetry were applicable and passed. Wire/network payload changes, Rust initialization, and cross-domain leakage were not applicable. The audit also replaced ambiguous boolean arguments with a named prompt policy and reduced the automatic test seam to the minimal retry callback.

frontend-ui-audit was intentionally skipped because its methodology excludes single bug-fix PRs and this change does not alter markup, styling, design-system usage, or accessibility behavior.

Area	Verdict	Evidence	Change or reason kept	Verification
Background work	keep	Existing visibility-aware scheduler remains the sole owner of startup/interval/focus/online/retry work	No timers or listeners added; all triggers share one reminder policy	Scheduler tests plus five-reason reminder matrix
Memory	keep	One localStorage record containing version + deadline	Record is overwritten per Later action and removed when expired/malformed or resolved	Persistence, expiry, malformed-state, skip/install tests
Scope/isolation	fix	Previous transient atom had no durable version scope	Reminder is keyed by update version; a newer version is never suppressed	New-version regression test
Rendering/hot path	keep	Existing prompt atom remains the only render gate	One synchronous storage read after update preparation; no new subscription	AppUpdater behavioral tests

Performance verdict: pass.

Verification

• npx vitest run src/scaffold/AppUpdater/index.test.ts src/scaffold/AppUpdater/appUpdaterCoordinator.test.ts src/scaffold/AppUpdater/appUpdaterScheduler.test.ts — 34 tests passed
• npx eslint src/scaffold/AppUpdater/index.tsx src/scaffold/AppUpdater/index.test.ts
• npm run typecheck
• git diff --check
• pre-commit lint-staged and scoped TypeScript checks