chore: bump plugin to v0.10.0

- Plugin now provides MCP server via mcp.json (local core-agent stdio)
- No manual .mcp.json needed — plugin auto-registers
- Portable paths (CORE_WORKSPACE env var, no hardcoded machine paths)

Co-Authored-By: Virgil <virgil@lethean.io>

claude/core/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "core",
   "description": "Core agent platform — dispatch (local + remote), verify+merge, CodeRabbit/Codex review queue, GitHub mirror, cross-agent messaging, OpenBrain integration, inbox notifications",
-  "version": "0.9.0",
+  "version": "0.10.0",
   "author": {
     "name": "Lethean",
     "email": "hello@host.uk.com"