refactor: consolidate agent/editor plugins under integrations/ (#5491)

Co-authored-by: Claude <noreply@anthropic.com>

integrations/mem0-plugin/plugin.json

@@ -0,0 +1,13 @@
+{
+  "id": "mem0",
+  "name": "mem0",
+  "version": "0.1.1",
+  "description": "Persistent semantic memory for Antigravity agents. Cross-session, user-level recall via the Mem0 Platform MCP server. 16 slash commands, lifecycle hooks for auto-capture and metadata enforcement.",
+  "author": { "name": "Mem0", "email": "support@mem0.ai" },
+  "publisher": "mem0ai",
+  "homepage": "https://mem0.ai",
+  "repository": "https://github.com/mem0ai/mem0",
+  "license": "Apache-2.0",
+  "keywords": ["memory", "persistence", "personalization", "mcp", "semantic-search"],
+  "contextFileName": "AGENTS.md"
+}