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.

package.json

@@ -30,6 +30,7 @@
     "ttrpg": "node --loader ts-node/esm ./src/cli/index.ts",
     "tttk": "node --loader ts-node/esm ./src/cli/index.ts",
     "gen:reference": "node --loader ts-node/esm ./scripts/generate-reference.ts",
+    "gen:skill-reference": "node --loader ts-node/esm ./scripts/generate-reference.ts --out ~/.agents/skills/tttk-authoring/reference.md",
     "test": "jest",
     "prepare": "npx husky",
     "prepublishOnly": "npm run build"