docs(D.2b): design spec — retail panel frame + live Vitals (Approach C)

Brainstormed design for the D.2b retail-look UI backend: our own KSML-style
markup + controls.ini stylesheet + retained-mode toolkit on Silk.NET (no
embedded browser, zero external deps — Approach C, chosen over Ultralight/CEF
and RmlUi for memory/dep-weight/faithfulness).

Spec 1 scope: an 8-piece dat-sprite window frame + live Vitals bars bound to
the existing VitalsVM, gated behind ACDREAM_RETAIL_UI=1, rendered via a reused
TextRenderer batch. Render-only (input/hit-test, AcFont glyphs, anchor solver,
LayoutDesc importer all deferred).

Grounded by a read-only research workflow (7 readers + gap-critic). The critic
corrected several stale memory/plan-doc facts now baked into the spec's
do-not-trust list: VitalsVM is a sealed class (not the old record); chrome
sprite IDs are unverified (Step-0 dat prove-out resolves them empirically);
controls.ini exists and #FFDBD6A8 is editbox text not a bg; DatCollection reads
are thread-safe; KSML is rich-text not the layout language (we mirror
ElementDesc).

Phase D.2b / Milestone M5 (parallelizable with M3/M4 — opened as a parallel
track while M1.5 stays the active critical-path milestone). Retires divergence
row TS-30 + adds one IA row when the chrome ships.

Also gitignores the /.superpowers/ visual-companion scratch dir.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitignore

@@ -26,6 +26,8 @@ references/*
 
 # Claude Code session state
 .claude/
+# Superpowers brainstorm visual-companion scratch (mockups regenerate; not source)
+/.superpowers/
 launch.log
 launch-*.log
 launch.utf8.log