When working under monguard, the root AGENTS.md is both incomplete (e.g., it doesn't say how to run monguard-specific tests) and inaccurate (e.g., `bazel run format` is unnecessary for rust-only changes under monguard). This change introduces a monguard-specific `AGENTS.md` and `CLAUDE.md` that imports it. It explains how to run all of the monguard-specific workflows locally.

At the same time, I changed the root `AGENTS.md`'s reference to rust 1.94.0 to 1.95.0 as that's what monguard actually uses.