The toolbar's search field now lives in AppKit's own NSSearchToolbarItem:
em(17) is the focused width (preferredWidthForSearchField), the resting
width is the item's own, and ⌘F becomes beginSearchInteraction — one call
that expands and focuses. Escape's empty-field exit collapses the field as
the keyboard leaves. resignsFirstResponderWithCancel is off so the staged
Escape survives the cancel button. The item ships its own live overflow row
and an above-.high visibility priority, so both custom-view workarounds
retire. The palette copy stays inert through an enablement round-trip the
item's searchField setter would otherwise overwrite.
The centering half of the card is blocked on a Design ruling (03 settles
"trailing") and is not built; the two-homes width question is filed.
Claude-Session: https://claude.ai/code/session_01CqjXB7ASoWtbyoGod68k97
NSToolbar through the existing HostedWindowController rather than
SwiftUI's toolbar — for reasons that are contract, not taste: 03's
transient-search clause is a decision over the toolbar's current
contents, which NSToolbar publishes and SwiftUI's API cannot answer;
Undo/Redo are the system's nil-target responder-chain actions so the
toolbar items validate exactly as the menu rows do (disabled on base
boards, alive in m8 unchanged); and the search item hosts the real
NSSearchField with explicit first-responder control. Customization is
all system furniture — Customize sheet, drag rearrange, display-mode
popup, overflow, autosaved per window kind. Board default: the search
field alone, trailing; catalog adds New Card, New Lane, Undo, Redo,
Show Trash, every action extracted from its menu command so no second
predicate exists. Card default: the Edit Body / Raw Source toggles and
Add Attachment, mirroring their commands' own predicates live via
observation tracking. Removing the search item keeps the promise —
⌘F surfaces the same field as a transient strip under the title bar,
persisting until the query clears, and an overflowed item that cannot
take the keyboard falls through to the strip too.
Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY
rzen