port: the contract I read is 3185 lines shorter than the contract

docs/port/HANDOFF.md on main is 926 lines, last touched 9ca1eb5 on 2026-08-29.
The live one is 4111 lines at 27938aa, +3930/-745 across 96 commits I have never
read, several of them addressed to the port by name. The Decoder writes HANDOFF
on origin/auto/no-disc-and-menu-captures; main is a hundred-odd commits behind
it; I open main's copy every iteration as instructed.

So the rule meant to prevent this cannot detect it. tools/port/blocked-provenance
recovers each row's derivation from history rather than memory -- git log -S on
the row's key phrase -- and all 27 open rows derive from 9ca1eb5, because
HANDOFF-on-main has not moved. A constant cannot separate a fresh row from a
rotten one. Withdrawn in BLOCKED.md: 'HANDOFF has not moved in four milestones'
was missing the qualifier that carried its meaning.

The tool's first version silently missed its own known positive: P6 looping vs
712cac8, whose 9.44 s answer this port already ships. 'looping' did not stem to
'loop', 'menu' was stoplisted, and a >=2-shared-words threshold dropped the rest.
The threshold was the defect -- two common words outscored one rare one -- so
ranking is now by log(N/df) with no cutoff at all, and the control passes at rank
1 of 7 without touching the stoplist. Every discard is counted: struck rows,
sub-rank pairs, stoplisted words. Same rule applied to check-claims, which now
reports the 40 occurrences it suppresses; the Decoder reached it the same day
from the opposite failure, a silent suppression path making a clean run
unfalsifiable.

The reading list found two open rows already answered: the plate's pulse period
(120, not 105) and the main menu having no idle self-return, which refutes the B
row's own reasoning.

Refutation attempted on '+0x08 is the loop length', the claim the port was about
to build on. It survives: their falsifier re-run on my own read of the disc gives
0 violations in 1781 records, and on the eight records this port animates their
table reproduces cell for cell. Adopted -- screen.rs exports loop_length_units
and ScreenView._loop_period prefers it, announcing any disagreement rather than
silently resolving it. The value does not change: authored/timing.json already
had 120 from a wall-clock measurement, so a disc field and an emulator stopwatch
agree while sharing no instrument.

Two asks filed: the field is exposed in no public API on any ref, so the port
reads four bytes it should not own; and eleven focus records declare the same
120-unit cycle while only the plate is authored to animate, which is behavioural
and not mine to infer.

Every asserting check passes; oracle RMSEs unchanged, as 120 == 120 predicts.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N7FiFFFwbvG2uxdcEh8HyF

port/scripts/screen_view.gd

@@ -405,6 +405,32 @@ static func settle_units(element: Dictionary) -> float:
 ## "this loops". What the disc says is 0° → 360° over `t`; what the RE agent
 ## measured is that the turn repeats rather than stopping. Those are two
 ## different sources and the day a loop flag is decoded, this goes.
+## The cycle length of a looping focus record, **derived in preference to authored**.
+##
+## The record header's `+0x08` says where the cycle restarts, and it is not the
+## last keyframe's time: the plate's glow ramps 0→80→0 over 105 units inside a
+## 120-unit cycle and rests dark for 15. The exporter now carries it as
+## `focus.loop_length_units`, so the period comes off the DISC.
+##
+## `authored/timing.json` had 120 already, from a wall-clock measurement of the
+## running game (≈2.37 s). **The two agree**, which is why this is a provenance
+## change and not a pixel change — an emulator stopwatch and a field on the disc,
+## sharing no instrument, landing on the same number. The authored value stays as
+## the fallback and as that second witness.
+##
+## A DISAGREEMENT IS ANNOUNCED, never silently resolved. Preferring one number
+## without saying so is how a measurement and a declaration drift apart for
+## milestones without anybody learning that they had.
+func _loop_period(focus: Dictionary, loop: Dictionary) -> float:
+	var authored := float(loop.get("period_units", 0.0))
+	var derived := float(focus.get("loop_length_units", 0.0))
+	if derived <= 0.0:
+		return authored
+	if authored > 0.0 and absf(derived - authored) > 0.5:
+		push_warning("focus record %s: the disc declares a %.0f-unit cycle, `authored/timing.json` says %.0f -- using the disc. One of them is wrong and this message is the only thing that will say so." % [String(focus.get("record", "?")), derived, authored])
+	return derived
+
+
 static func spin_period_units(element: Dictionary) -> float:
 	var frames: Array = element.get("keyframes", [])
 	if frames.size() != 2:
@@ -645,7 +671,7 @@ func _draw_focus(element: Dictionary) -> void:
 			var was := holding
 			holding = false
 			var lt: float = time_units if loop_phase_units < 0.0 else loop_phase_units
-			pose = pose_at(fe, fposmod(lt, float(loop["period_units"])))
+			pose = pose_at(fe, fposmod(lt, _loop_period(focus, loop)))
 			holding = was
 		var pivot := _vec(fe.get("pivot", [0, 0]))
 		var pos := _vec(pose.get("pos", [0, 0]))