docs(skill): Generate the tttk reference catalog

Enrich known.ts with element/role details, inline specs, and dice notation, and render them from reference.ts. Add gen:skill-reference and ~ expansion in --out so the skill copy can be regenerated.

The skill's reference.md is now generated; its extra authoring content moved to layout.md, yaml-tag.md, csv.md, and markdown.md.

scripts/generate-reference.ts

@@ -7,6 +7,7 @@
  */
 
 import { mkdirSync, writeFileSync } from "fs";
+import { homedir } from "os";
 import { dirname, resolve } from "path";
 import { renderReference } from "../src/cli/validate/reference.js";
 
@@ -15,7 +16,16 @@ function argValue(flag: string): string | undefined {
   return index >= 0 ? process.argv[index + 1] : undefined;
 }
 
-const out = resolve(argValue("--out") ?? "docs/reference.md");
+/** Expand a leading `~` so the skill copy can be targeted cross-platform. */
+function expandHome(path: string): string {
+  if (path === "~") return homedir();
+  if (path.startsWith("~/") || path.startsWith("~\\")) {
+    return resolve(homedir(), path.slice(2));
+  }
+  return path;
+}
+
+const out = resolve(expandHome(argValue("--out") ?? "docs/reference.md"));
 mkdirSync(dirname(out), { recursive: true });
 writeFileSync(out, renderReference(), "utf-8");
 console.log(`wrote ${out}`);