ADFA-5119 docs(state-spine): finding 5 is now reached almost only through finding 3

Re-read against the tree rather than assumed. Inside the state nothing has
changed: H_NO_LIBRARY is still the header for every no-system case and still the
one state that gets no button, and the row is now non-clickable with a comment
saying it is meant to be. ADFA-5104 improved where the two wrong doors land —
the hub explains why it refuses instead of only refusing — which is better to
read and still a refusal.

What changed is the entrance. A failed install now keeps the install marker and
lands in recovery; Cancel clears setup_complete and lands in the wizard. S1 is
left with essentially one way in: a failed "Copy from a phone", which marks the
flag before any transfer exists.

So findings 3 and 5 are now one problem. Closing finding 3's remaining half —
writing setup_complete on a verified install rather than on intent — makes this
dead end unreachable without touching the Home screen at all. The fix is not a
button; it is not writing the flag on intent.

Author: luisguzman-adfa