Phase 4: add appendSuffix — optional reinject message suffix.

Configurable trailing note after skill block per settings.suffix (SPEC §5.3).

Co-authored-by: Cursor <cursoragent@cursor.com>

src/expand.ts

@@ -18,3 +18,12 @@ export function readSkillBody(filePath: string): string {
 export function formatBlock(meta: SkillBlockMeta, body: string): string {
 	return `<skill name="${meta.name}" location="${meta.filePath}">\nReferences are relative to ${meta.baseDir}.\n\n${body}\n</skill>`;
 }
+
+/** Append optional reinject suffix after skill block (SPEC §5.3). */
+export function appendSuffix(block: string, suffix: string | undefined): string {
+	const trimmed = suffix?.trim();
+	if (!trimmed) {
+		return block;
+	}
+	return `${block}\n\n${trimmed}`;
+}