nopy: add init command with bundled NOPY.LLM.md guide

`nopy init` writes a starter .nopyrc.json and NOPY.LLM.md — an LLM-facing
usage guide covering cubes, config, variables, sessions, and pyinfra — into
the working directory. Existing files are skipped unless --force. The guide
ships as dist/templates/NOPY.LLM.md, resolved relative to the module so it
works from source and from an installed package alike.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ce5atB2tXDXyz2jd9s1bqE

packages/nopy/package.json

@@ -43,7 +43,7 @@
   },
   "scripts": {
     "clean": "rm -rf dist .tsbuildinfo",
-    "build": "tsc && cp src/cubes/*.mjs dist/cubes/",
+    "build": "tsc && cp src/cubes/*.mjs dist/cubes/ && mkdir -p dist/templates && cp src/templates/*.md dist/templates/",
     "prepack": "pnpm run build",
     "link:local": "pnpm run build && npm link",
     "nopy": "tsx src/nopy.cli.ts",