refactor(protos): move internode compat manifest send-site assertions into owning crates
Promotes the rolling-upgrade dual-write manifest from a test-only constant in rustfs-protos into the public rustfs_protos::compat_manifest module, moves the JSON-encoder send-site assertions into the crates that own the asserted sources (ecstore remote_disk.rs for requests, the rustfs binary node_service/disk.rs for responses), and splits the scanner Phase-0 overlap inventory so its heal- and ecstore-owned halves live in those crates. Adds a cross-crate include_str!/include! guard with fixture self-tests to scripts/check_layer_dependencies.sh so a library crate can never again read another crate's Rust source at compile time, and records the rule in docs/architecture/crate-boundaries.md.
Part of rustfs/backlog#1884.