What opening a screen needs: the screen's own services and its item lists',
the stack and the navigation, and the process services every assembled handle
holds (the handle's checkpoint() runs with them).
Every entry that runs an enter burst and assembles its handle declares it —
enterFrame, enterRoot, switchToTab, the launch contract and the screen
set's catalog entry — so a layer built exactly to a declared requirement
either carries the checkpoint's process state or fails to compile; it never
builds and then dies with "Service not found" on the handle's checkpoint().
What opening a screen needs: the screen's own services and its item lists', the stack and the navigation, and the process services every assembled handle holds (the handle's
checkpoint()runs with them).Every entry that runs an enter burst and assembles its handle declares it —
enterFrame,enterRoot,switchToTab, the launch contract and the screen set's catalog entry — so a layer built exactly to a declared requirement either carries the checkpoint's process state or fails to compile; it never builds and then dies with "Service not found" on the handle'scheckpoint().