feat: skill generator with manifest, frontmatter parser and mapping-doc matrix

scripts/frontmatter.ts

@@ -0,0 +1,42 @@
+// Minimal YAML-subset frontmatter parser for upstream SKILL.md files.
+// Supports exactly what mattpocock/skills uses (census 2026-10-14, @49dd158): top-level
+// `key: value` scalars, double/single-quoted strings with \" escapes, and nested blocks
+// (e.g. `metadata:`) which are skipped. test/generate.test.ts asserts every vendored skill
+// parses with non-empty name+description, so an upstream format change fails the build
+// instead of silently producing a broken manifest.
+
+export type Frontmatter = Record<string, string>
+
+export function parseFrontmatter(content: string): { frontmatter: Frontmatter; body: string } {
+  const text = content.replace(/^\uFEFF/, "")
+  if (!text.startsWith("---\n") && !text.startsWith("---\r\n")) {
+    return { frontmatter: {}, body: text }
+  }
+  const end = text.indexOf("\n---", 3)
+  if (end === -1) return { frontmatter: {}, body: text }
+  const raw = text.slice(text.indexOf("\n") + 1, end + 1)
+  const body = text.slice(text.indexOf("\n", end + 1) + 1)
+
+  const frontmatter: Frontmatter = {}
+  for (const line of raw.split(/\r?\n/)) {
+    if (!line || /^\s/.test(line) || line.trim() === "---") continue // nested block or separator
+    const m = /^([A-Za-z][\w-]*):\s*(.*)$/.exec(line)
+    if (!m) continue
+    frontmatter[m[1]] = unquote(m[2].trim())
+  }
+  return { frontmatter, body }
+}
+
+function unquote(value: string): string {
+  if (value.length >= 2 && value.startsWith('"') && value.endsWith('"')) {
+    return value.slice(1, -1).replace(/\\"/g, '"').replace(/\\\\/g, "\\")
+  }
+  if (value.length >= 2 && value.startsWith("'") && value.endsWith("'")) {
+    return value.slice(1, -1).replace(/''/g, "'")
+  }
+  return value
+}
+
+export function isUserInvoked(frontmatter: Frontmatter): boolean {
+  return frontmatter["disable-model-invocation"] === "true"
+}