chore(design-sync): add Reactive Resume UI sync inputs (#3216)

* chore(design-sync): add Reactive Resume UI sync inputs

Sync inputs for the claude.ai/design "Reactive Resume" project — the
@reactive-resume/ui design system (39 primary components).

- .design-sync/config.json — converter config (synth-entry, 202->39 card
  prune, overlay/grid cardMode overrides, cssEntry, tsconfig, buildCmd)
- .design-sync/build-css.mjs + tw-entry.css — compile Tailwind v4 globals.css
  to a self-contained stylesheet (inlined IBM Plex font), emit real .d.ts,
  and create the workspace self-symlink the converter needs
- .design-sync/previews/*.tsx — 39 authored preview compositions
- .design-sync/conventions.md — design-agent usage header (readmeHeader)
- .design-sync/NOTES.md — re-sync notes, gotchas, and risks
- packages/ui/tsconfig.emit.json — declaration emit for real prop contracts

Build artifacts (dist/types, .ds-compiled.css, ds-bundle, .cache) are gitignored.

Claude-Session: https://claude.ai/code/session_01R8Aq8F1nTuvJwfut7g3DVE

* chore(knip): ignore .design-sync inputs and drop stale es-toolkit ignore

- Ignore .design-sync/** (design-sync tooling: build-css.mjs + authored
  previews are standalone, not part of the app import graph — knip --fix was
  deleting them and failing the autofix job).
- Remove es-toolkit from apps/server ignoreDependencies: it's now really used
  (apps/server/src/http/health.ts imports withTimeout), so the ignore is stale.

Claude-Session: https://claude.ai/code/session_01R8Aq8F1nTuvJwfut7g3DVE

.design-sync/previews/ComboboxRoot.tsx

@@ -0,0 +1,30 @@
+import {
+	ComboboxContent,
+	ComboboxEmpty,
+	ComboboxInput,
+	ComboboxItem,
+	ComboboxList,
+	ComboboxRoot,
+} from "@reactive-resume/ui/components/combobox";
+
+const skills = ["TypeScript", "React", "Node.js", "GraphQL", "PostgreSQL", "Kubernetes"];
+
+// Base UI Combobox — items passed to Root, rendered open (defaultOpen).
+// cfg.overrides.ComboboxRoot pins cardMode: single + viewport with room below.
+export const Open = () => (
+	<div style={{ width: 320, padding: 16, paddingBottom: 200 }}>
+		<ComboboxRoot items={skills} defaultOpen>
+			<ComboboxInput placeholder="Add a skill…" />
+			<ComboboxContent>
+				<ComboboxEmpty>No skills found.</ComboboxEmpty>
+				<ComboboxList>
+					{(item: string) => (
+						<ComboboxItem key={item} value={item}>
+							{item}
+						</ComboboxItem>
+					)}
+				</ComboboxList>
+			</ComboboxContent>
+		</ComboboxRoot>
+	</div>
+);