shape-doctor.py pin_restore: where the side taken in a conflicted shape pin does not read as a pin, the NEXT still takes that side, and run as printed it leaves the doctor naming the same NEXT again #752

Goal: when a merge leaves contracts/shape-pin.yaml conflicted and the side the doctor would take does not read as a pin, the NEXT either takes the side that reads or names no line. It never prints a NEXT that, once run, brings the same NEXT back.

Filed by lane openRepoShape-3 under v1.1.1, on Brett Heap's word of 2026-10-16T13:35:28Z ("yes create v1.1.1"). Lane 3's reviewer RV-b found it while reviewing #736 (#687). It is not a regression: main does the same.

What happens. RV-b measured this on main 66b230ed and on #736's head 3dfe2fde:

• The state: stage 2 of contracts/shape-pin.yaml is restaged as files: [, which is unparsable, and stage 3 reads.
• The NEXT is git checkout --ours -- contracts/shape-pin.yaml …, which takes the unreadable side.
• Once run, the doctor names the same NEXT again, because the pin it took still does not read.

What to do:

• In pin_restore, take the side whose pin reads. If neither reads, name no NEXT and say in the why that neither side's pin reads.
• Pin both cases with tests that run the printed NEXT as printed and check what the doctor says after it.

Lands after: #736.