fix: re-hide macos dock icon after parentless dialogs

[afonsojramos]

Summary

Since v7.0.0 the macOS dock icon occasionally reappears even though Gitify runs as a dock-hidden (accessory) app, and only a restart re-hides it.

Investigation

Tested live on macOS by driving the real built app (hidden window, setVisibleOnAllWorkspaces, accessory policy) and measuring app.dock.isVisible():

• Reproduced: app.dock.hide() can be silently dropped when it races an app activation transition. In the experiment, hide() called 500ms after the dock became visible left the icon showing; a later hide() succeeded. electron-menubar calls dock.hide() very early in startup, so a lost race there leaves the icon stuck for the whole session. A restart re-rolls the race, which matches "occasionally showing" + "restart restores it".
• Not reproduced (on this machine/OS): the parentless dialogs (updater "restart to install", first-run prompt) did not flip the dock. Kept the dialog-path re-hides anyway as cheap defense, since dialog-driven activation is version-dependent macOS behavior.
• DevTools (detached) also did not affect the dock.

Fix

1. Startup re-assert (the evidence-backed part): ~2s after menubar ready, if the dock is visible, call app.dock.hide(). Guarded on isVisible() because dock.hide() also deactivates the app, so it must not run unconditionally near window-show paths (that would steal the popup's focus and trigger the blur auto-hide).
2. Dialog-close re-hides (defensive): re-assert hidden after the updater dialog is dismissed and after the first-run prompt closes.

Tests

• startup.test.ts: re-hides when the dock is visible after the delay; leaves it alone when already hidden.
• updater.test.ts: dismissing the update dialog re-hides the dock.
• first-run.test.ts: the dock is re-hidden after the prompt closes.

pnpm check, tsc --noEmit, and the affected suites pass (27 tests).

Closes #3069

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[setchy]

should this logic be within electron-menubar based on this config param being set?

gitify/src/main/index.ts

Line 34 in c83528d

showDockIcon: false, // Hide the app from the macOS dock