[devin-ai-integration]

Summary

Replaces the stock NSSegmentedControl in TabStripView with a custom row of profile tabs (option B from the tab-strip investigation). The public TabStripView contract (update(windows:selectedWindowID:), onSelectWindow, onReorderWindow, onMove, …) is unchanged; two callbacks are added.

Built and tested only via macOS CI (the dev box is Linux); not yet exercised interactively on a Mac.

Layout, left to right:

[browser icon menu] [tab][tab][tab]…[ghost profile tabs]   [+N ▾] [+]

• TabButton (custom-drawn NSView): selected tab = profile-color tint + ring + semibold label; hover/pressed fills; close × on hover (reserved space, so no relayout on hover); middle-click closes. Selection fires on mouse-down; a >4pt drag switches to reorder, where the tab follows the pointer (lifted) and neighbours animate into new slots (NSAnimationContext, 0.16s).
• TabStripLayout (pure, unit-tested): clamps tabs to 96–180pt, water-fills shrink (widest shrink first), and once tabs no longer fit at 96pt moves the rest into an overflow +N menu, always keeping the selected tab visible. Leftover width is filled with dashed ghost tabs for picker-visible profiles that have no open window (click → open that profile).
• Duplicate labels: TabStripLayout.labels(for:) → ["Personal", "Work", "Window 3", "Personal 2"].
• Browser icon is now a menu button (Settings / Rescan / Quit — same items as the existing right-click menu, which still works on the strip and tabs).
• + button pops a menu of ProfileChoice.pickerChoices for this browser.
• Inactive dimming: ContainerController.update calls tabStrip.setBrowserActive(frontmost pid == selected pid); tints desaturate and labels fade.
• Scroll over the strip cycles tabs (one step per trackpad gesture / wheel notch).
• Accessibility: row is .tabGroup; window tabs are .radioButton with selected value, "Window i of n" help, and a "Close Window" custom action; ghosts are buttons labelled "Open …".

New plumbing:

tabStrip.onCloseWindow  -> AccessibilityController.close(window)   // presses kAXCloseButtonAttribute
tabStrip.onOpenProfile  -> BrowserLauncher.openWindow(browser:profile:)
//   chromium: --user-data-dir=… [--profile-directory=id] --new-window
//   firefox:  [-P name] -new-window about:newtab

BrowserLauncher.launch now shares a private run(browser:arguments:) helper; its arguments are unchanged.

Things worth checking on a Mac (none exercised yet):

• Hover/close affordance in the non-activating panel while another app is frontmost (tracking areas use .activeAlways).
• Firefox -new-window about:newtab from the command line, and Chromium --new-window against an already-running instance.
• Drag-reorder feel with mixed tab widths.

Link to Devin session: https://app.devin.ai/sessions/3feca0145cfc45de90b3030ab28f7a89
Open in Devin Desktop: https://app.devin.ai/desktop/session/3feca0145cfc45de90b3030ab28f7a89?variant=devin
Requested by: @darvid

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring