re(ui): the paint-order tie-break is undecodable from the bundle

Q3 was delivered as "decoded: a u16 layer key at +0x0A". The audit last
iteration showed the key does not fully order a screen -- elements
sharing a key are tied, and on the title that tie-break decides two total
occlusions. This searches for what breaks the tie, and closes it as a
negative with reach.

The game paints the five tied ptlogo_back2eff glows in the order
eff1, eff2, eff5, eff3, eff4. Three static structures were searched:

1. The declaration table. Entries 14-18 are byte-identical apart from the
   pivot, which is only half the sprite's own size.

2. The T8aD headers. All five carry identical +0x04 (0x8832) and
   identical +0x08/+0x0A (32899, the key itself), differing only in
   position and tile count. Searched exhaustively -- every offset
   0x00-0x7f, u8/u16/u32, ascending and descending:

     fields sorting to the MEASURED order:              0
     fields sorting to the DECLARATION order (control): 64

   The control is the point: 64 fields can be found that reproduce a
   known ordering, so the scan finds ordering fields when they exist. It
   finds none for the order the game uses.

3. The RATC child order -- a genuinely different permutation on other
   screens -- gives eff1..eff5 here, declaration order again.

All three static orderings give eff1..eff5; the game gives eff1,2,5,3,4.
That agrees with ui-screen-runtime's conclusion from the other direction:
the game builds a reordered child list at load time and paints that.

Q3 now reads honestly: the layer key is decoded and orders 4 of the 5
measured bundles exactly; the tie-break within a key is undecodable, and
a consumer must use a measured order or accept declaration index as an
arbitrary stand-in. The port's exposure remains 2 overlapping tied pairs
on EXTRAS.

METHOD: an exhaustive field search needs a positive control, or "found
nothing" is worthless.

docs/port/HANDOFF.md

@@ -29,7 +29,7 @@ authored version can be deleted.
 |---|---|---|---|
 | Q1 | keyframe time unit + ramp shape | ✅ answered, 🟡 one gap | ramp is **linear**; **2 units per rendered frame**; **`1 unit = 1/60 s` — settled**, the idle title presents at 28.5 fps so the game is 30 Hz. 🟡 **The interpolation law is settled; the group TIMELINE for multi-keyframe elements is not** — `palogo_gamearts` is still at full alpha 9 frames after its declared `a=32`, and its declared 80-frame fade-in never draws — [`ui-keyframe-time-unit.md`](../re/ui-keyframe-time-unit.md) |
 | Q2 | which build is which screen state | ✅ answered | `GP_TITLE` is **8 screens shipped twice, EN/JP**: 4/7 title art, 2/3 the `PRESS Ⓐ` plate, 5/8 main menu, 6/9 `EXTRAS`, 0/1 and 10/11 two unidentified `DELTASABER` plates — [`ui-title-build-map.md`](../re/ui-title-build-map.md) |
-| Q3 | paint order for the six screens | ✅ answered | **decoded**: a `u16` layer key at `+0x0A` of each `T8aD` sprite header, stable-sorted with declaration index; unkeyed elements get an implied key. Confirmed on 5 measured orders + `EXTRAS` vs a capture. One residual: the **tie-break** is unknown and bites on one element of the title — [`structures/ui-paint-order-key.md`](../re/structures/ui-paint-order-key.md) |
+| Q3 | paint order for the six screens | ✅ answered, ❔ tie-break | **decoded**: a `u16` layer key at `+0x0A` of each `T8aD` sprite header, stable-sorted with declaration index; unkeyed elements get an implied key. Confirmed on 5 measured orders + `EXTRAS` vs a capture. One residual: the **tie-break** is unknown and bites on one element of the title — [`structures/ui-paint-order-key.md`](../re/structures/ui-paint-order-key.md). ⚠️ **The key does not fully order a screen**: elements sharing a key are tied, and the tie-break is ❔ **undecodable from the bundle** — declaration table, `T8aD` header (exhaustive: every offset 0x00–0x7f at u8/u16/u32, both directions, **0** fields match the measured order against **64** for the control) and the RATC child order all give the same order the game does *not* use. Your exposure is **2 overlapping tied pairs on `EXTRAS`** — [`structures/ui-paint-order-derived-check.md`](../re/structures/ui-paint-order-derived-check.md) |
 | Q4 | button → GamePart | ✅ answered | **measured** which screen all **5** buttons open — `NEW GAME` → `DIFFICULTY` → `SELECT DATA`, not a hang. The **GamePart id is still a name match**, not a measurement — [`menu-navigation-semantics.md`](../re/menu-navigation-semantics.md) |
 | Q5 | navigation semantics | ✅ answered | **measured**: initial focus varies boot to boot (2× `TUTORIAL`, 2× `NEW GAME`); ⬆⬇ one step, **wraps both ends**; ⬅➡ do nothing; Ⓑ returns to the parent **with focus restored**; Ⓑ on the main menu → title; Ⓑ on the title → nothing — [`menu-navigation-semantics.md`](../re/menu-navigation-semantics.md) |
 | Q6 | boot sequence + what drives it | ✅ answered | sequence **measured** end to end; the driver is **code, not data** — four search spaces closed, so the port **authors** the sequence — [`boot-config-and-gamepart-registry.md`](../re/boot-config-and-gamepart-registry.md) |