Runs the pre-registered A/B for the two movement changes in HEAD: the
time-indexed bullet heat (TR_TFIL_HEAT_TIME, fca8993) and the removal of the
invented virtual centre pillar (d0750ab). One frozen binary from HEAD vs real
DrussGT: 6 arms x 10 runs x 7 rounds = 60 battles, 420 rounds, 0 failed.
Judged on damage/run and ROUND WINS only (hit rate and hits-taken are context):
hit rate would have inverted the verdict again - tau3 has the best pooled hit
rate of all arms (11.56%) and the fewest round wins (20/70).
RESULT (vs the reconstructed pre-change mover "old"):
heat-time HURTS. tau3/tau5/tau9 lose 1.3-1.7 wins/run (p=0.0010-0.0125) and
deal 22-38 less damage/run (p=0.004-0.047); tau15 is a wash on wins (p=0.64)
and 22 damage/run lower (p=0.046). Nothing improves either metric.
pillar removal does nothing measurable. old vs pillaoff: +5.7 damage/run
(p=0.71), +0.5 wins/run (35 vs 30, p=0.43), 30.8 MORE damage taken/run
without the pillar (p=0.040). The mechanism check proves the knob works
(centre-box occupancy 0.09% -> 2.37%, p<0.0001; range 469 -> 443 px,
p=0.0002), so this is a real behaviour change that buys nothing. At n=10 the
pillar contrast is inside the MDE (33 damage/run, 1.2 wins/run), so this is
not a proven regression.
Flags that the shipped default (pillar removed) should be reverted to the
TR_TFIL_PILLAR_ON behaviour; heat-time stays off.
Adds tools/ab/arms_heat_pillar.txt and tools/ab/ab_mechanism.py (per-tick
mechanism check: central-box occupancy, range distribution, live enemy-bullet
proximity) plus the captured summary/report fixtures.
SirStone