feat(cli): --version, status, doctor commands (v0.1.3)

Three Tier-2 polish commands for debugging + discoverability:

- claudemesh --version / -v: print CLI version (baked from
  package.json at build time via Bun JSON import).
- claudemesh status: WS-probe each joined mesh's broker, report
  reachability per mesh. Exit 1 if any broker unreachable.
- claudemesh doctor: run 6 preconditions — Node>=20, claude on PATH,
  MCP registered, hooks registered, config file parses + chmod 0600,
  mesh keypairs validate. Each check has a pass/fail + fix hint.
  Exit 0 if all pass.

Help text now leads with version (\"claudemesh v0.1.3 —\").

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

apps/cli/src/version.ts

@@ -0,0 +1,8 @@
+/**
+ * Bundled version string. Bun inlines the package.json JSON at build
+ * time, so the shipped binary carries the exact version that was
+ * published.
+ */
+import pkg from "../package.json" with { type: "json" };
+
+export const VERSION: string = pkg.version;