openGym v1.2.5 — the MCP server

Nothing in the app changed. This release adds an optional, read-only MCP server
so an AI assistant you already run can answer questions about your own training,
off the same files your instance already writes. If you don't use one, this
release is invisible to you.

Contributed by @Pengboi (#19) — the first feature in openGym written by someone
other than me.