chore(cli): bundle for node, prep for npm publish

Makes @claudemesh/cli installable globally via npm without requiring
bun on user machines. (Bun stays the dev runtime; bundled output is
node-compatible.)

- bun build --target=node --outfile dist/index.js produces a 2.69MB
  standalone bundle with node-shebang banner
- package.json: add description/keywords/author/license/homepage/
  repository, set bin to ./dist/index.js, files=[dist, README, LICENSE],
  publishConfig.access=public, engines.node >=20
- prepublishOnly auto-runs the build
- pin zod from catalog: to 4.1.13 (npm rejects catalog: refs)
- swap Bun.spawnSync → node:child_process.spawnSync in install.ts
  (the only Bun-global usage in the package)
- strip shebang from src/index.ts (banner supplies it post-bundle)

install command now runs in two modes:
- BUNDLED (npm i -g): detects dist/index.js path, writes MCP entry
  with command "claudemesh" (relies on the global bin shim on PATH)
- SOURCE (bun src/index.ts, dev): preflights bun, writes MCP entry
  with command "bun <absolute-path> mcp"

verified end-to-end:
- node dist/index.js --help prints usage ✓
- node dist/index.js install writes correct ~/.claude.json ✓
- node dist/index.js mcp | tools/list returns all 5 tools ✓
- bun src/index.ts install (dev mode) still works ✓

NOT PUBLISHED YET — @claudemesh/cli is owned by an unrelated project
on npm. Awaiting user decision on alternative name (claudemesh-cli,
@alezmad/claudemesh-cli, or new org scope). Bundle is name-agnostic
and will reuse regardless.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/cli/src/index.ts

@@ -1,4 +1,3 @@
-#!/usr/bin/env bun
 /**
  * @claudemesh/cli entry point.
  *