Creator ruling (2026-10-30):
- EDIT off + ON-AIR armed → the primary button reads "Go Live" and runs the livestream.
- EDIT on + ON-AIR armed → the same button reads "Test Stream" and runs the test broadcast.
- REC armed (or nothing armed) → "Start Recording", whatever EDIT says; there is no test
recording, and an unarmed start records locally rather than doing nothing.
So the fifth button was redundant: `ShowTestButton` no longer feeds any control. The decision is a
pure function (`Models/SessionStartDecision`) so the whole matrix is testable without a window;
`PrimaryStartCommand` follows the same kind, so label and action cannot disagree.
Guard: SessionStartDecisionTests pins the four cases, including the no-dead-ends fallback that my
first version got wrong (unarmed returned Live instead of Record — the test caught it).
Note for the v1 gate: the "hide TEST at v1" item is now satisfied by construction — the test path
is a mode of the primary button, not a separate control.