fix(mem0-agent): add required userConfig title to the plugin manifest

The loader validates userConfig.<key>.title as a required string; without it the
install fails with 'invalid manifest file'. Manifest shape now matches the v1
plugin's exactly.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

integrations/mem0-agent/.claude-plugin/plugin.json

@@ -4,7 +4,7 @@
   "description": "Coding-agent memory that remembers your preferences, decisions and hard-won gotchas across sessions, machines and editors",
   "author": {
     "name": "Mem0",
-    "url": "https://mem0.ai"
+    "email": "support@mem0.ai"
   },
   "homepage": "https://docs.mem0.ai",
   "repository": "https://github.com/mem0ai/mem0",
@@ -13,7 +13,8 @@
   "userConfig": {
     "api_key": {
       "type": "string",
-      "description": "Mem0 API key from https://app.mem0.ai. Stored in your OS keychain, never written to a file.",
+      "title": "Mem0 API Key",
+      "description": "Your Mem0 Platform API key (starts with m0-). Get one at https://app.mem0.ai/dashboard/api-keys. Stored in your OS keychain, never written to a file.",
       "sensitive": true,
       "required": true
     }