re(ui): kill two candidate meanings for the T8aD 0x02 bit, and fix attribution

The bit at +0x04 was recorded as a real field with its meaning "not
diagnosed", noting ptlogo_back2eff is 0x8830 "despite its name". That note
rested on a size match -- and its size is ambiguous, which is the trap
this corpus already records.

First, a sound attribution. T8aD headers appear in the bundle in RATC
CHILD ORDER, verified on GP_TITLE build 4 against an independent property
-- each header's decoded dimensions versus the dimensions the named child
should have: 18 of 18 match, 0 mismatches. Two of those eighteen share a
size (ptlogo_back2eff and ptlogo_back2eff5, both 1133x280), so a size-keyed
lookup cannot separate them; ordering can. Index 12 is back2eff5 (0x8832,
bit set), index 14 is back2eff (0x8830, bit clear). The documented
counterexample is real and correctly attributed -- now on evidence.

Two candidate meanings tested and refuted:

  bit <=> name contains "eff"        REFUTED: ptlogo_back2eff is an eff
                                     name with the bit clear. All 10
                                     bit-set sprites are eff names, so
                                     the implication holds one way only.
  bit <=> the element is transient   REFUTED: pteff03/pteff03a carry the
                                     bit and run to t=250, ramping to
                                     a=255 and holding.

Up close, the exception pair differs in two header words: +0x04
0x8832/0x8830 and +0x08 0x8083/0x8081 -- layer keys 32899 and 32897. They
are NOT duplicates: their alpha summaries agree to one decimal (4.5%
opaque, 86.7% clear, mean 19.3) but a pixel compare gives max abs diff 21.
Two renditions of one image at one size, which is why the summaries were
not trusted.

Still not diagnosed, and said so -- but the search space is two smaller
and the attribution beneath it is now sound.

METHOD: T8aD headers sit in child order, use that not the size; and
identical summary statistics are not identical data.

docs/port/HANDOFF.md

@@ -120,7 +120,7 @@ authored version can be deleted.
   ⚠️ **Correlation only — untested.** Nothing yet shows it *means* additive; the
   test is to blend bit-`0x02` sprites additively and re-correlate the title
   against the capture. Note `ptlogo_back2eff` is `0x8830` despite its name, so
-  this is a field and not a naming pattern. ❔ Not diagnosed.
+  this is a field and not a naming pattern. ❔ Not diagnosed — but two candidate meanings are now dead: **not** "the name contains `eff`" (`ptlogo_back2eff` is an `eff` name with the bit clear — confirmed by a validated name→header pairing, not a size guess) and **not** "the element is transient" (`pteff03`/`pteff03a` carry the bit and persist to `t=250`). ⚠️ Practical note for an asset pipeline: `T8aD` headers appear in **RATC child order** (18/18 verified on build 4 against decoded dimensions), which is the only sound way to attribute a header to a name when two sprites share a size — and two here do.
   ⚠️ **The rotated draw is NOT the swoosh.** It was identified as the swoosh by
   elimination; that is **refuted** — its quads span y −209…925 in screen space,
   the swoosh is a band at y 126…360. ✅ **It is the two `ptloop` sweeps**