[melvincarvalho]

Closes the two sample-check gaps left by the critic pass (#13).

• mautrix (Python): pyright reported an error on @client.on(EventType.ROOM_MESSAGE). mautrix 0.21.1 types Syncer.on() as returning a union, so the decorator can't be checked. The sample now registers the handler with add_event_handler, which is fully typed. pyright reports 0 errors, and an offline run under env -i registers one handler. The page says why.
• matrix-sdk (Rust): re-checked with rustc 1.96.1, the crate's MSRV, in a toolchain installed in a scratch directory. cargo check passes without --ignore-rust-version. No page change was needed.