re: index and cross-references for the record layout and the loading screens

docs/port/HANDOFF.md

@@ -300,8 +300,8 @@ items MISSION parks as emulator-blocked.
 
 | | Question | State | Answer / link |
 |---|---|---|---|
-| 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). ✅ **REPLICATED 2026-08-29 — for ANIMATION, read `+36` as the time the NEXT pose is reached.** Three elements across two screens: `palogo_gamearts` and `palogo_seta` hold full alpha for **83 frames** and `palogo_sqex` for **≥77**, where the current reading predicts **6–8** and the shifted one **80–102**. The elements that cannot discriminate (the `_eff` glows, on which the linear law was measured) fit both. ⚠️ Our decoder still defaults to the other reading (`SYLPHEED_KF_TIME_SHIFT=1` to flip) because it changes `rest()` on one element — but that is an unsound fallback guessing either way, so **static rendering is unaffected and animation timing should use the shift** |
-| 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) |
+| Q1 | keyframe time unit + ramp shape | ✅ answered | ramp is **linear**; **2 units per rendered frame**; **`1 unit = 1/60 s` — measured**, the idle title presents at 28.5 fps so the game is 30 Hz — [`ui-keyframe-time-unit.md`](../re/ui-keyframe-time-unit.md). ✅ **The group timeline is now DECODED too (2026-08-29) and the gap is closed**: a placement group is `frames` records of `{u32 time; 36-byte pose}` after an 8-byte header, so a pose's time is the word **before** it, pose 0's time is the group's lead-in word, and **every** pose is timed — including the last, which nothing could time before. Disc-wide over 13 991 groups with controls; the old reading makes **0 of 1 042** multi-segment alpha ramps constant-rate against 857 of 1 540. `SYLPHEED_KF_TIME_SHIFT` is retired (it had the association right but left pose 0 untimed, which is the whole reason it appeared to cost 13.1 % of build 7). Static renders are byte-identical — [`ui-keyframe-record-layout.md`](../re/ui-keyframe-record-layout.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`, and ✅ **0/1 and 10/11 are the LOADING screen** — two variants, plain and dressed, decoded from their `pgloading_*` element names (2026-08-29). 🟡 which of the two is `LOADING` vs `LOADING2` is undecided; 🟡 the English member of a pair is the one in the first half of the data segment — [`ui-title-build-map.md`](../re/ui-title-build-map.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) |
@@ -1174,7 +1174,7 @@ here until 2026-08-28 and is now settled.)
 | 🟡 | **GamePart ids behind the buttons** (Q4) | the *screens* are measured; the ids are a name match onto the executable's class names |
 | 🟡 | **the boot transitions in code** (Q6) | both levels decoded — phase at `this+132` (`entry→2`, `2→0`, `2→3`, `3→4`, `4→2`) and state at `this+136` inside phase 4. Phase 0 = splash (`LOGO`), phase 2 = title + `PRESS Ⓐ`, phase 4 = menu. Unknown: what the event *numbers* mean |
 | 🟡 | **Ⓑ leaving the main menu** (Q5) | **upgraded 2026-08-29 (later).** The idle half of this objection is **refuted**: the main menu does not self-return for **≥ 60 s** untouched, and the ~8–10 s idle belongs to the **title**. Ⓑ is delivered (Canary logs `vk=5801`) and is the only input in ≥ 100 s before the return, so the **ordering is measured**; the latency is not (a backlogged probe void). The footer point stands — the main menu is still the only screen not advertising Ⓑ — [`menu-navigation-semantics.md`](../re/menu-navigation-semantics.md#-refutation-attempt-2026-08-29--the-main-menus-own-footer-does-not-advertise-ⓑ) |
-| ❔ | **builds 0/1 and 10/11**, the `DELTASABER` plates (Q2) | never seen anywhere in the boot path, the title-side screens or the attract loop. A mission load is the remaining candidate and this container kills runs before one completes |
+| 🟡 | **which loading bundle is `LOADING` and which `LOADING2`** (Q2) | ✅ the pair is identified — they are the loading screen, decoded from `pgloading_*` element names, and the executable names exactly two. What is open is only the assignment, and nothing observed maps a name to a bundle. ⚠️ The old row here said the pair was *unidentified `DELTASABER` plates never seen running*; that is withdrawn — a loading screen is not supposed to appear on the title path |
 
 (An earlier version of this table called the audio items blocked on "an emulator
 whose audio path can be observed". That was wrong — this build already has