979 parameter pairs, 977 distinct repunit values, 2 collision groups.
Only Goormaghtigh solutions have equal repunits.
Closest non-Goormaghtigh: 28× above 10^-6 threshold.
No Baker. No Matveev. Pure integer arithmetic.
Also documents bug in unknown_fails_rrc theorem statement:
h : repunit x m = repunit y n forces threshold = 0,
contradicting ¬mergeAdmissible.
