Align protocol runtime with spec boundaries

Move demo leaf echo behavior out of the core protocol runtime, treat procedure IDs as opaque protocol fields, and return direct registered children in endpoint introspection to match the spec.

src/protocol/tests/protocol.rs

@@ -16,11 +16,11 @@ fn packet_framing_roundtrip_preserves_header_and_payload() {
         packet_type: PacketType::Call,
         src_path: path(&["root", "caller"]),
         dst_path: path(&["root", "callee"]),
-        dst_leaf: Some("echo".to_owned()),
+        dst_leaf: Some("service".to_owned()),
         hook_id: None,
     };
     let call = CallMessage {
-        procedure_id: "unshell.echo.v1.alpha.invoke".to_owned(),
+        procedure_id: "example.service.v1.invoke".to_owned(),
         data: vec![1, 2, 3, 4],
         response_hook: Some(HookTarget {
             hook_id: 7,
@@ -45,7 +45,7 @@ fn header_and_call_validation_reject_invalid_combinations() {
         packet_type: PacketType::Data,
         src_path: path(&["peer"]),
         dst_path: path(&["host"]),
-        dst_leaf: Some("echo".to_owned()),
+        dst_leaf: Some("service".to_owned()),
         hook_id: None,
     };
     assert_eq!(
@@ -59,11 +59,11 @@ fn header_and_call_validation_reject_invalid_combinations() {
         packet_type: PacketType::Call,
         src_path: path(&["caller"]),
         dst_path: path(&["callee"]),
-        dst_leaf: Some("echo".to_owned()),
+        dst_leaf: Some("service".to_owned()),
         hook_id: None,
     };
     let invalid_call = CallMessage {
-        procedure_id: "unshell.echo.v1.alpha.invoke".to_owned(),
+        procedure_id: "example.service.v1.invoke".to_owned(),
         data: Vec::new(),
         response_hook: Some(HookTarget {
             hook_id: 5,
@@ -79,18 +79,10 @@ fn header_and_call_validation_reject_invalid_combinations() {
 }
 
 #[test]
-fn procedure_validation_accepts_introspection_and_rejects_bad_shapes() {
+fn procedure_validation_accepts_introspection_and_non_empty_opaque_ids() {
     assert_eq!(validate_procedure_id(""), Ok(()));
-    assert_eq!(
-        validate_procedure_id("unshell.echo.v01.alpha.invoke"),
-        Ok(())
-    );
-    assert_eq!(
-        validate_procedure_id("contains spaces"),
-        Err(ValidationError::ProcedureId(
-            "procedure identifier should use alphanumeric characters, dots, and underscores"
-        ))
-    );
+    assert_eq!(validate_procedure_id("example.service.v01.invoke"), Ok(()));
+    assert_eq!(validate_procedure_id("contains spaces"), Ok(()));
 }
 
 #[test]

src/protocol/tests/tree.rs

@@ -1,7 +1,7 @@
 use alloc::{borrow::ToOwned, string::String, vec, vec::Vec};
 
 use crate::protocol::tree::{
-    DefaultRouteProvider, Endpoint, Ingress, LeafBehavior, LeafNode, LeafSpec, LocalEvent,
+    ChildRoute, DefaultRouteProvider, Endpoint, Ingress, LeafNode, LeafSpec, LocalEvent,
     ProtocolEndpoint, RouteDecision, RouteProvider, TreeNode,
 };
 use crate::protocol::{
@@ -19,8 +19,8 @@ fn tree_node_paths_flatten_explicitly() {
         children: vec![TreeNode::Endpoint {
             segment: "branch".to_owned(),
             leaves: vec![LeafNode {
-                name: "echo".to_owned(),
-                procedures: vec!["unshell.echo.v1.alpha.invoke".to_owned()],
+                name: "service".to_owned(),
+                procedures: vec!["example.service.v1.invoke".to_owned()],
             }],
             children: vec![TreeNode::Endpoint {
                 segment: "leaf".to_owned(),
@@ -60,11 +60,10 @@ fn protocol_endpoint_introspection_returns_leaf_summary() {
     let mut endpoint = ProtocolEndpoint::new(
         path(&["root"]),
         Some(Vec::new()),
-        Vec::new(),
+        vec![ChildRoute::registered(path(&["root", "child"]))],
         vec![LeafSpec {
-            name: "echo".to_owned(),
-            procedures: vec!["unshell.echo.v1.alpha.invoke".to_owned()],
-            behavior: LeafBehavior::Echo,
+            name: "service".to_owned(),
+            procedures: vec!["example.service.v1.invoke".to_owned()],
         }],
     );
 
@@ -96,11 +95,12 @@ fn protocol_endpoint_introspection_returns_leaf_summary() {
     .expect("introspection payload should deserialize");
 
     assert!(response.end_hook);
+    assert_eq!(introspection.sub_endpoints, vec!["child".to_owned()]);
     assert_eq!(introspection.leaves.len(), 1);
-    assert_eq!(introspection.leaves[0].leaf_name, "echo");
+    assert_eq!(introspection.leaves[0].leaf_name, "service");
     assert_eq!(
         introspection.leaves[0].procedures,
-        vec!["unshell.echo.v1.alpha.invoke".to_owned()]
+        vec!["example.service.v1.invoke".to_owned()]
     );
 }
 
@@ -113,7 +113,7 @@ fn invalid_hook_peer_emits_local_fault_event() {
         .make_call(
             path(&["server"]),
             None,
-            "unshell.echo.v1.alpha.invoke",
+            "example.service.v1.invoke",
             Some(hook_id),
             vec![1, 2, 3],
         )
@@ -128,7 +128,7 @@ fn invalid_hook_peer_emits_local_fault_event() {
             hook_id: Some(hook_id),
         },
         &DataMessage {
-            procedure_id: "unshell.echo.v1.alpha.invoke".to_owned(),
+            procedure_id: "example.service.v1.invoke".to_owned(),
             data: vec![9],
             end_hook: false,
         },