v0.12.0

Fixed

• The MCP server moved from a top-level mcp_server package to
  postgres_aiops.mcp_server. Every AIops tool used to ship its own top-level
  mcp_server, so installing two of them into one environment merged the two
  into one package: postgres-aiops-mcp could start another tool's server, and
  postgres-aiops undo wrote audit and undo rows into the other tool's home
  directory. Installs through uvx, the Claude Code plugin or the OpenClaw
  bundle were isolated and unaffected. The postgres-aiops-mcp command is
  unchanged; only code that imported mcp_server directly must now import
  postgres_aiops.mcp_server.