chore(addon): publish dev addon version 7.12.0.dev1840 [skip ci]

Author: github-actions[bot]

homeassistant-addon-dev/config.yaml

@@ -1,6 +1,6 @@
 name: "Home Assistant MCP Server (Dev)"
 description: "Development channel - AI assistant integration via MCP (unstable)"
-version: "7.12.0.dev1837"
+version: "7.12.0.dev1840"
 slug: "ha_mcp_dev"
 url: "https://github.com/homeassistant-ai/ha-mcp"
 stage: experimental