docs: backlog — two items solved, four opened by them

docs/re/BACKLOG.md

@@ -56,6 +56,39 @@ where translucent sprites overlap.
   cheapest is a screen whose object is resident at the same time as the title's.
 * ❔ 341 builds now composite in an order no capture has checked.
 
+## ✅ SOLVED (2026-08-19) — `_eff` glows were being dropped as focused states
+
+`compose` skips focused-state records, and the flag matched a trailing `f` in
+the name. `_eff` — this UI's word for a glow layer — ends in one. 2 458 elements
+matched; **54** have the base element they would be the focused version of, and
+the other 2 404 across 864 bundles are glows. Requiring the pair recovers 587 of
+them in composable builds; `GP_OPTIONS` went from two floating brackets to an
+actual window. The `opt ` link was tried as a replacement and **refuted** — 221
+targets, 2 suffix-matches, and the targets include `pjnet_bg.rat`.
+See [`structures/ui-focus-and-effect-elements.md`](structures/ui-focus-and-effect-elements.md).
+
+## ✅ SOLVED (2026-08-19) — the developer-logo splash can be rendered
+
+`is_build` required a `.rat` layout child; the splash has none (its elements name
+their sprites directly). New `is_composable` + opt-in `--all` on the screen
+commands. The splash draws 6/7 elements, glows first, in the order measured off
+the running game — so the second of the two measured paint orders is now
+checkable instead of merely recorded.
+See [`structures/ui-composable-bundles.md`](structures/ui-composable-bundles.md).
+
+**Opened by those two:**
+
+* ❔ **`.prm` primitives are not decoded.** Every composite is missing them. On
+  the splash the measured order puts `palogo_eff0.prm` **first** — it is the
+  backdrop. Cheapest first step: dump the `.prm` child bytes of a bundle that has
+  exactly one and see whether it is a solid quad with a colour.
+* ❔ **What marks a focused state in the file.** The pairing rule that shipped is
+  a naming convention, not a decoded field. `kind = 0x3002` is a button record;
+  whether a bit of `kind` marks the focused variant is the cheapest probe.
+* ❔ **What makes a bundle a screen rather than a fragment.** `is_composable`
+  admits 1 786 extra bundles, mostly 2–5-element button+glow fragments.
+* ❔ **What `opt ` links.** Refuted as focus; unexplained otherwise.
+
 The investigation that got here follows, kept in full because most of it is
 refutations that were worth the cost.