Measures WHERE the lava picker loses tiles, per pick:
reachable hull -> CoolestLevels=2 distinct-value filter -> path heat
filter -> draw set -> chosen. TR_TFIL_DIAG (default off) fills
TfilLoss*; TR_TFIL_DANGER_THRESHOLD (default 10.0, the shipped const)
makes the cutoff sweepable offline. No decision logic changed: the guard
test proves the diag-on move stream is byte-for-byte the diag-off one.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
