521b0b1f85
BLOCKED said the record-layout change touches five things: pose_at, settle_units, spin_period_units, exit_ramp_units and the plate. I checked two, reported that, and did not work the rest of the list. `spin_period_units` required "the first timed and the second untimed". Under the corrected layout the ring reads t=0 rot=0 and t=120 rot=360 -- both timed -- so the rule returned 0 and THE FOCUS RING STOPPED SPINNING. Nothing reported it: a period of 0 is a legal "this element does not spin". Rewritten to take the SPAN between the two poses: 120 - 0 = 120 units, the same number the old rule produced, which is evidence the corrected layout is self-consistent rather than merely different. Verified the way P5 verified it, by bit-identity one period apart on the ring's own 60x60 box so the ptloop sweeps cannot confound it: 0 at +120 units (twice), 8.61 at a quarter period, 8.88 at half. Three wrong instruments on the way, and the sequence is the lesson. A whole-frame `max` saturates on one rotating edge (adjacent frames scored 131 with a mean of 0.022). A live --menu filmstrip jitters by up to a frame, which is ~3 degrees of ring. And a whole-frame comparison is dominated by the sweeps, which move 480 px over one ring period. `--focus=<id>` was added so a --screen run can draw a focus record deterministically, which is what made the check reproducible. THE PLATE'S PERIOD IS NOW 105, THE DISC'S OWN GROUP LENGTH, and it disagrees with the measurement. The ambiguity the entry carried is gone -- it used to say the cycle might restart at t=6 rather than 0 and that nothing separated them; the group now runs t=0 to t=105, both at alpha 0, and there is one reading. But 105 units is 1.750 s, or 1.906 s scaled by the factor the ring shows between its declared 120 and its measured 2.177 s -- about 17% below all four corpus timings (2.12 / 2.19 / 2.34 / 2.31). The old 129 gave 2.34 s, at the top of the range, which is why it looked right. 129 was the last timed keyframe plus exit_ramp_units, and that constant is deleted. A period built on a constant that no longer exists cannot stay even though it fitted better, so the port ships the disc's number and says it is wrong. Verified bit-identical 105 units apart, 0.83 at 30 units. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF
Authored decisions
Everything here is a decision we made, not something the disc said. It is
hand-written, committed, and survives a re-export — unlike export/, which is
regenerated wholesale and must never be hand-edited.
Every entry carries a why. When the RE agent decodes the real answer, delete
the entry and let the exporter emit it; that deletion is the measure of
progress.
See docs/FORMAT.md for the schemas and docs/BLOCKED.md for which HANDOFF
question each placeholder is standing in for.