port: re-derive black_hold_units against four measurements rather than inherit it

They answered ask #2 -- the gap is deterministic, not a load -- and held me to
re-stating the choice against four measurements (0, 6, 4, 6) rather than the three
it was made on. That is my own standard for check-all's stale allowance turned
around.

The arithmetic moved against 0: it costs 2.0x the best fit on four measurements
against 1.7x on three, and is now the minority outcome, wrong on 3 of 4 where a
uniform 6 is wrong on 2 of 4.

Still 0, because the reason was never the fit -- it adds no black the game does
not have, and is measured-correct for a real transition rather than for an average
of them. Picking 6 because it appears twice is choosing a mode from four samples
when their finding is that a rule exists and nobody has found it.

But one leg is gone and is not being kept quietly: part of the case for 0 was that
the quantity might be machine-dependent and unauthorable. It is not. That removes
an excuse without supplying a value.

Added a tripwire: if the gap is non-zero in most transitions and no rule emerges,
omitting a real quantity stops being caution and becomes a different invention.
The port is wrong by 4-6 units on three of four known transitions and the why now
says so.

Also records as settled: the outgoing ramp is the declared final ramp, my {8,10,10}
against their measured multiset, two independent routes.

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

authored/timing.json

@@ -145,27 +145,38 @@
   ],
   "black_hold_units": 0,
   "black_hold_why": [
-    "0, AND THAT IS NOT 'RIGHT' -- IT IS THE VALUE THAT INVENTS NOTHING.",
+    "0, RE-DERIVED against FOUR measurements, not inherited from three.",
     "",
-    "This was 9 units, measured in the draw stream. The Decoder has now measured",
-    "the black gap on THREE transitions off the running game and it is not a",
-    "constant: menu->title 0 units, title->menu 4, EXTRAS->menu 6. Not a",
-    "per-button property, not a per-direction property. Their recommendation is to",
-    "treat this as unauthored rather than uniform-at-9.",
+    "The Decoder's measured black gaps are now 0, 6, 4, 6 units across four",
+    "transitions. When this was set to 0 the multiset was (0, 4, 6), and they held",
+    "me to re-stating the choice against the new data rather than carrying it --",
+    "the same standard I applied to check-all's stale allowance.",
     "",
-    "9 was outside the measured range entirely -- wrong for all three, by +9, +5",
-    "and +3, i.e. up to a sixth of a second of black the game does not show.",
+    "The arithmetic moved AGAINST 0 and it is worth writing down rather than",
+    "burying: a uniform 6 is wrong on 2 of 4 transitions for a total error of 8;",
+    "0 is wrong on 3 of 4 for a total of 16. Choosing 0 cost 1.7x the best fit on",
+    "three measurements and costs 2.0x on four. 0 is now the MINORITY outcome --",
+    "three of four transitions do have a gap.",
     "",
-    "WHY 0 AND NOT 4. A uniform 4 minimises total error across the three samples",
-    "(6 units against 0's 10). That is FITTING THREE SAMPLES, and a fit chosen for",
-    "its residual is the thing this corpus keeps having to withdraw. 0 has a",
-    "reason that is not a fit: it adds no black the game does not have, which is",
-    "the same tie-breaker `input_during_transition` already uses in this file --",
-    "the choice that invents the least. It is also measured-CORRECT for one real",
-    "transition, which no other uniform value beats on principle.",
+    "IT IS STILL 0, and the reason is unchanged because it was never the fit: 0",
+    "adds no black the game does not have, which is the tie-breaker",
+    "input_during_transition already uses in this file, and it is measured-correct",
+    "for a real transition rather than for an average of them. Picking 6 because",
+    "it appears twice is choosing a mode from four samples with no rule behind it.",
     "",
-    "The error is now a MISSING gap of at most 6 units on two transitions rather",
-    "than an INVENTED one of up to 9 on all three. Delete this entry the day the",
-    "rule is known; the Decoder cannot state it yet and neither can I."
+    "ALSO CHANGED: the gap is NOT machine-dependent. It was defensible to hold 0",
+    "partly because the quantity might be a load and therefore unauthorable; the",
+    "Decoder has now shown it is deterministic to the frame -- bundle size runs the",
+    "wrong way, and a repeat run moved press-to-first-change by ~12 frames while",
+    "the gap did not move at all. So this is a real game quantity with a rule",
+    "nobody has found, not noise. That REMOVES an excuse for 0 without supplying a",
+    "value.",
+    "",
+    "TRIPWIRE, because 'invent nothing' can stop being conservative: if the gap is",
+    "non-zero in most transitions and no rule emerges, systematically omitting a",
+    "real quantity is no longer the cautious choice -- it is a different invention.",
+    "Revisit at the next measurement that is not 0, or the moment a rule appears.",
+    "The port is currently wrong by 4-6 units on three of four known transitions",
+    "and says so here rather than in a number that looks decided."
   ]
 }