proto becomes bxcore, the one shared crate (M5b task 00)

Done the way the owner asked and the spike mapped: the crate and the
manifests renamed, then what the build reported fixed. Layers: 138
"proto unresolved" errors across 169 files; cargo fmt reordering
imports; six fixture paths built as strings in brokerd's and bxctl's
tests, which the compiler cannot see, and comments naming
crates/proto/; the crate-dependency check and its self-test. One more
the spike did not reach: a `\nproto =` key inside a printf format in
the self-test, which a word-boundary replacement skips because `n` and
`p` are both word characters.

make gate: gate: ok, 944 tests; no new entry in /tmp.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

crates/loopd/tests/channel.rs

@@ -5,14 +5,14 @@
 
 mod support;
 
+use bxcore::{
+    Envelope, ErrorCode, Message, PROTOCOL_VERSION, SessionId, Turn, TurnEvent, read_frame,
+    write_frame,
+};
 use loopd::channel::{Context, serve};
 use loopd::llama::Client;
 use loopd::memory::NoMemory;
 use loopd::tools::Registry;
-use proto::{
-    Envelope, ErrorCode, Message, PROTOCOL_VERSION, SessionId, Turn, TurnEvent, read_frame,
-    write_frame,
-};
 use std::os::unix::net::{UnixListener, UnixStream};
 use std::path::PathBuf;
 use std::sync::Arc;
@@ -30,7 +30,7 @@ struct Loopd {
     home: Home,
 }
 
-fn start(replies: Vec<proto::ToolResponse>) -> Loopd {
+fn start(replies: Vec<bxcore::ToolResponse>) -> Loopd {
     let home = Home::new();
     let server = FakeServer::start();
     let cfg = home.config(&server.socket);
@@ -177,7 +177,7 @@ fn tool_calls_are_reported_by_name_only() {
         tool_events[1],
         &TurnEvent::ToolResult {
             name: "read_file".to_string(),
-            class: proto::DataClass::Private,
+            class: bxcore::DataClass::Private,
             truncated: false
         }
     );
@@ -292,7 +292,7 @@ fn bad_frames_get_an_error_and_a_close() {
     stream
         .set_read_timeout(Some(Duration::from_secs(5)))
         .unwrap();
-    let msg = Message::Error(proto::WireError {
+    let msg = Message::Error(bxcore::WireError {
         code: ErrorCode::Internal,
         detail: String::new(),
     });
@@ -311,7 +311,7 @@ fn bad_frames_get_an_error_and_a_close() {
     assert!(
         matches!(
             reply.msg,
-            Message::Error(proto::WireError {
+            Message::Error(bxcore::WireError {
                 code: ErrorCode::BadMessage,
                 ..
             })
@@ -319,7 +319,7 @@ fn bad_frames_get_an_error_and_a_close() {
         "{reply:?}"
     );
     assert!(
-        matches!(read_frame(&mut stream), Err(proto::FrameError::Closed)),
+        matches!(read_frame(&mut stream), Err(bxcore::FrameError::Closed)),
         "then the connection is closed"
     );
 
@@ -333,7 +333,7 @@ fn bad_frames_get_an_error_and_a_close() {
     assert!(
         matches!(
             reply.msg,
-            Message::Error(proto::WireError {
+            Message::Error(bxcore::WireError {
                 code: ErrorCode::BadMessage,
                 ..
             })
@@ -365,7 +365,7 @@ fn bad_frames_get_an_error_and_a_close() {
     assert!(
         matches!(
             reply.msg,
-            Message::Error(proto::WireError {
+            Message::Error(bxcore::WireError {
                 code: ErrorCode::BadVersion,
                 ..
             })