v1: Filled neighbors + inequality count
v2: Candidate count (≤2 = LIKELY)
LIKELY → Find the shape:
● Lock — forced value
◐ Signal — inequality pair
═ Beam — row/col sweep
◈ Resonance — chain network
⟶ Vision — trial placement
Mistake Budget:
Easy: 4 | Medium: 3 | Hard: 2 | Expert: 2