fix(menubar): suppress restore during startup settling period to prevent icon parade

[7a6163]

Problem

Addresses the "icon parade" reported in #224 — icons continuously shuffling for 10–15 seconds. The root cause is that restoreItemsToSavedSections and restoreSavedItemOrder fire on every didLaunchApplicationNotification (1 s debounce). During login, 20+ apps load over ~30 seconds, each triggering its own restore cycle that conflicts with the next, producing cascading icon moves.

A secondary trigger is app update checks (e.g. BetterTouchTool), which briefly remove and re-add a menu bar icon, causing the same back-to-back restore cascade outside of login.

Solution

Startup settling period

Introduce isInStartupSettling, a flag that blocks restore operations and saveSectionOrder() calls for a fixed window after performSetup() completes:

• 30 s when ProcessInfo.processInfo.systemUptime < 60 (login item / auto-launch boot)
• 5 s otherwise (manual restart, app-update scenario)

During the period, every didLaunchApplicationNotification still triggers a cache cycle so the UI stays accurate, but neither restoreItemsToSavedSections nor restoreSavedItemOrder runs.

saveSectionOrder() is also suppressed during settling to protect the UserDefaults-loaded reference order from being overwritten by transient physical positions before restore has run.

When the period expires, one final cacheItemsRegardless(skipRecentMoveCheck: true) enforces the user's saved layout against whatever macOS placed items. skipRecentMoveCheck: true prevents the restore from being silently skipped by the 5 s move cooldown in case relocateNewLeftmostItems stamped a timestamp near the end of the window.

Re-entrancy safety

startupSettlingTask: Task<Void, Never>? tracks the in-flight task. A subsequent performSetup() call cancels the previous task before starting a new one. The cancelled task uses do/catch on Task.sleep to exit cleanly without touching shared state.

A settlingDeadline: ContinuousClock.Instant? is stored so that re-entry computes max(existingDeadline, newDeadline), preventing a second call from truncating the original 30 s login window if systemUptime has crossed 60 s by then.

Layout reset interaction

resetLayoutToFreshState() cancels the settling task and clears the flag immediately — a user-initiated reset is authoritative and must not be blocked by an in-flight settling period.

Move cooldown bump

Both restoreItemsToSavedSections and restoreSavedItemOrder raise their move-operation cooldown from 2 s to 5 s, providing more separation between consecutive automatic restores when apps restart in quick succession.

Changes

Single file: Thaw/MenuBar/MenuBarItems/MenuBarItemManager.swift (+89 / -5)

Test plan

• Login item boot — enable Launch at Login, reboot, verify no icon shuffle during the first ~30 s after login
• App update trigger — use BetterTouchTool's "Check for updates" and verify icons do not shuffle
• Normal app restart — quit and relaunch an app that has a hidden menu bar item; verify it is restored to the correct section within ~5–8 s
• Reset Layout during boot — open Settings and press Reset Layout within 30 s of login; verify the reset takes effect immediately without waiting for settling to expire
• Permission re-grant — revoke and re-grant Screen Recording permission during the settling window; verify settling deadline is preserved (not truncated)
• Show/hide — verify IceBar show/hide behaviour is unaffected during and after the settling period

⚠️ More testing needed. The 30 s / 5 s thresholds and the systemUptime < 60 boundary are heuristics. Feedback on edge cases — especially on slower machines or unusual login configurations — would be very helpful before merging.

Fixes #224