Mark recap Case-B design retrofit done; log cleanup-execution learnings

- Flip recap's Case-B /design backfill from "in flight" -> done in
  ROADMAP/AGENTS: contract extracted + two-phase conformance cleanup
  shipped (recap app 0.2.161).
- Add three cleanup-execution Field notes to guides/design.md:
  CSS-value-position var-ify scoping, exclude standalone no-:root
  exports, border-radius-clamp capsule snapping.
- Note the standalone-export literal-hex exception in design-checker.md's
  Color dimension.

guides/design.md

@@ -302,6 +302,23 @@ us things. Brand facts never go here; only generalizable process/distillation kn
   `_imports/` are correctly skipped; instead write `inspiration/README.md` pointing at the
   harvested source files + the brand icon as the de-facto reference, and copy the icon into
   `brand/`. That preserves the *why/where* record the folder convention exists for.
+- *(Case-B cleanup-execution run, 2026-06-17, recap)* **Scope an inline-hex→`var()` sweep to
+  CSS-value position, not to `style=` attributes.** Convert a hex only where the character before
+  `#` is not a quote/backslash (i.e. it's preceded by `:`/space/`,`). That one rule auto-dodges the
+  spots that must stay literal — hex held in JS *logic* (`const c = …`, quoted ternary branches like
+  `${on ? "#1e293b" : …}`), SVG `fill=`/`stroke=` attributes, and `<meta theme-color>` — without a
+  hand-kept exclusion list, and it beats `style="…"` boundary-matching (which breaks on inner quotes
+  inside `${…}`). Verify after: every introduced `var()` resolves against `:root`, and 0 mapped hexes
+  remain in CSS-value position (proves no silent misses).
+- *(Case-B cleanup-execution run, 2026-06-17, recap)* **Exclude standalone generated documents from
+  var-ification.** A self-contained export (share page, print/PDF view, email body) ships its own
+  `<style>` with no `:root`, so `var(--token)` won't resolve there — its literal hex is correct, not
+  drift. Identify those regions (by line range or by the builder fn) and skip them. Snapping off-scale
+  *values* inside them is still fine, since that's a literal change.
+- *(Case-B cleanup-execution run, 2026-06-17, recap)* **`border-radius` clamps to half the shorter
+  side — use it to snap capsules for free.** A pill-shaped control (e.g. an 18px-tall count badge at
+  radius 9) renders identically at any radius ≥ half its height, so snapping *up* to the next scale
+  step (9→10) is on-scale **and** pixel-identical. Snap capsules up, not down, to avoid a visible change.
 
 ## Final report