chore(release): 1.5.4

Make /collaborate slash command self-contained so it works without a registered mailbox-collaborate skill in the session.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

node/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@kuns/claude-mailbox",
-  "version": "1.5.3",
+  "version": "1.5.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@kuns/claude-mailbox",
-      "version": "1.5.3",
+      "version": "1.5.4",
       "license": "MIT",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.29.0",

node/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@kuns/claude-mailbox",
-  "version": "1.5.3",
+  "version": "1.5.4",
   "description": "Standalone MCP mail server that lets parallel Claude sessions coordinate with each other.",
   "type": "module",
   "bin": {