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/memoryd/src/serve.rs

@@ -5,7 +5,7 @@ use std::os::unix::net::{UnixListener, UnixStream};
 use std::sync::{Arc, Mutex, MutexGuard};
 use std::time::Duration;
 
-use proto::{
+use bxcore::{
     DataClass, Empty, Envelope, ErrorCode, MemoryAdminReply, MemoryArgs, MemoryBlockReply,
     MemoryCall, MemoryCommand, Message, PROTOCOL_VERSION, RecallArgs, Reindexed, Timestamp,
     ToolResponse, WireError, read_frame, write_frame,
@@ -205,8 +205,8 @@ impl Memoryd {
     fn call(&self, call: MemoryCall) -> ToolResponse {
         let state = self.lock();
         let result = match call.request.tool.as_str() {
-            proto::memory::RECALL => self.recall(&state, &call),
-            proto::memory::MEMORY => self.memory(&state, &call),
+            bxcore::memory::RECALL => self.recall(&state, &call),
+            bxcore::memory::MEMORY => self.memory(&state, &call),
             _ => {
                 return ToolResponse::Failed {
                     message: "memoryd runs only recall and memory".to_string(),