One active build, and the pin that follows it

Exactly one build is the Tabby you use: it is what the taskbar pin launches, it carries a badge, and it is never deletable — so there is always a working Tabby left on the machine. Nothing here can create a taskbar pin, because Windows removed that verb in 1809, but a Start menu entry can be written and a pin made from it is then kept aimed at the active build.

With several builds on the machine, "the Tabby you use" is whatever the taskbar pin happens to point at — and nothing stopped you deleting it.

Exactly one build is active. It is what the pin launches, it carries a badge, and it is never deletable — so together with "the build this window runs from is never deletable", you must hand the crown to another build before you may delete this one. There is always a working Tabby left on the machine.

• Nothing here can create a taskbar pin. Windows removed the "pin to taskbar" shell verb in 1809 and blocks it for automation. What a pin is, though, is a shortcut in the Quick Launch user-pinned folder, and rewriting its target is allowed — so: pin Tabby by hand once, and the page keeps that pin aimed at the active build.
• What you pin is a Start menu entry, and that part can be created. Windows offers Pin to Start and Pin to taskbar only for things it considers Start menu apps, which is what "I can't pin my fork" turned out to be. Builds → Options writes one.
• One stable shortcut name, never the build's. Pinning copies the file, so a name that changed with the active build would strand every pin made from it.
• On first run the page adopts whatever the pin already points at, rather than nominating a build and overruling the desktop.
• A source build can be pinned because of --dev. A .lnk cannot carry environment variables, and dev mode was previously only expressible as TABBY_DEV=1, so the shortcut would have started an Electron with no plugins.
• The icon is rewritten with the target — and for a source build it comes from the checkout's own .ico, since the target there is electron.exe, whose icon is Electron's.

• Putting an app in someone's Start menu because they clicked "make active" is not this page's call, so the shortcut is retargeted only when it already exists.