feat(cli): v0.5.5 — ping_mesh diagnostic tool

Sends test messages to self through the full pipeline per priority
and measures round-trip timing. Reports send→ack and send→receive
latency. Detects broker priority gating (status=working holds next/low).

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

apps/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "claudemesh-cli",
-  "version": "0.5.4",
+  "version": "0.5.5",
   "description": "Claude Code MCP client for claudemesh — peer mesh messaging between Claude sessions.",
   "keywords": [
     "claude-code",