[a-team-app]

F1 now opens the shared Help dialog from MentalDesk.Tui. Everywhere (left) lists every global command that has a key and can run right now, under its menu heading in menu-bar order, then Other. Your place's keys are on the right. Because it reads your bindings each time it opens, a rebind shows the new key, a command you've just given a key appears, and an unbound or disabled one drops out. The status bar now always ends with Press F1 for help at its right edge, with the cursor position just before it, and the command is called Show keys.

Closes #512

Things that change what you see beyond the task:

• Diff shows up as a heading too, between Go and Review, since it's a menu on the bar. The task's list left it out.
• Go to line is an Editor command, so binding it puts it in the editor's column, not Everywhere. The tests use Open recent folder (File) as the unbound global command that gets a key.
• Other includes Ctrl+1…Ctrl+9 (Focus editor tab 1–9), Esc Focus editor and F10 Show menu. These are bound but have no menu item. That's nine rows for the tab keys alone.
• A key the place's column already lists (the sidebar tab keys, next/previous tab, the find options) isn't repeated under Everywhere.
• Find in file and Replace in file only show in Everywhere while a file is open. With no tab, Ctrl+F and Ctrl+H open the Find pane.
• Enter no longer closes the dialog. The library's dialog closes on Esc only, as the task's out-of-scope note says.
• The status bar's default message is now just TuiCode, since the help key has its own slot. In an 80-column terminal the message on the left gets cut shorter to make room.
• The Help menu's letter for Show keys is k (it was g, for Getting Started).

Also fixes main's red build: #581's UnsavedEditsHostTests still used ConfirmView, which #582 removed, so it now takes Don't save by its key like the other confirm tests.

a-team try tuicode 583