Work on implementing the protocol.

src/protocol/mod.rs

@@ -1,40 +1,17 @@
-//! # Protocol Module
+//! Canonical UnShell protocol modules.
 //!
-//! All wire types used by the UnShell protocol.
-//!
-//! ## Module layout
-//!
-//! ```text
-//! protocol/
-//!   mod.rs      ← you are here; re-exports everything
-//!   types.rs    ← PacketHeader, TreeRequest, TreeResponse, Handshake*
-//!   content.rs  ← content-type string constants
-//! ```
-//!
-//! ## Quick start
-//!
-//! ```rust
-//! use unshell::protocol::{
-//!     PacketHeader, PacketType,
-//!     TreeRequest, RequestType,
-//!     content,
-//! };
-//!
-//! let header = PacketHeader {
-//!     dst_path: "/agents/abc123/shell/exec".into(),
-//!     src_path: "/operator/sess1".into(),
-//!     packet_type: PacketType::Request,
-//! };
-//!
-//! let request = TreeRequest {
-//!     request_id: 1,
-//!     request_type: RequestType::CallProcedure,
-//!     content_type: content::UTF8_STRING.into(),
-//!     data: b"ls -la".to_vec(),
-//! };
-//! ```
+//! The wire model matches `PROTOCOL.md` directly.
 
-pub mod content;
+pub mod codec;
+pub mod introspection;
 mod types;
+pub mod validation;
 
-pub use types::*;
+pub use codec::{
+    FrameBytes, FrameError, ParsedFrame, decode_frame, deserialize_archived_bytes, encode_packet,
+};
+pub use introspection::{EndpointIntrospection, LeafIntrospection, LeafIntrospectionSummary};
+pub use types::{
+    CallMessage, DataMessage, FaultMessage, HookTarget, PacketHeader, PacketType, ProtocolFault,
+};
+pub use validation::{ValidationError, validate_call, validate_header, validate_procedure_id};