Reproduce arcade menu transitions

docs/re_gc_menu_exe.md

@@ -90,9 +90,11 @@ list deltas rather than complete scenes:
 - `COLT` carries RGBA multiplication, including authored visibility fades;
 - `ASRC` contains the exported `play();`, `stop();`, and target actions.
 
-`gc::BuildRvbSnapshot` now accumulates those deltas through a selected label
-and advances `play()` entry frames to their following `stop()` frame. This is
-why hidden templates and transition masks no longer appear together.
+`gc::BuildRvbSnapshot` accumulates those deltas through a selected label. Its
+snapshot state can either advance a `play()` entry to the following `stop()`
+or request a relative animation frame globally or per MovieClip path. Per-path
+evaluation is required here because the selected transition must advance while
+unrelated child loops remain at their authored steady frames.
 
 MTX starts with `MTX\0`; each payload is a DDS whose first dword was replaced
 by the container. Restoring `DDS ` yields a standard DDS. RVB `ImageN` maps to
@@ -137,9 +139,15 @@ actual formulas and spacings:
 - `(7 - count) * 0.5 * 68`, with the row anchored at `426 + 16`;
 - `(9 - count) * 0.5 * 52`, with the row anchored at `433 + 16`.
 
-The remaining visual work is outside this recovered static scene snapshot:
-the executable-owned player/status HUD in the blank upper band, continuous
-timeline interpolation, and the exact transition timing between task states.
+`FUN_00447170` also supplies the transition timing used by the executable. Song
+slot changes interpolate linearly over `0.125` seconds. The list enters/exits
+over `0.375` seconds and shifts by one viewport width using exponent `4` easing.
+The row plates retain their full dimensions; their opacity and the title scale
+use the slot values `0.7`, `0.8`, `0.9`, and `1.0`. The desktop selector now
+combines these executable-owned values with frame-based RVB entry, exit, sort,
+focus, difficulty-change, and decision states. Confirmation is a distinct
+`jf_decision`/`jf_mode_decision` phase before the task exit timeline; collapsing
+both phases is why an immediate screen switch does not resemble the cabinet.
 
 ## Common and navigator layers