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/brokerd/src/ledger/answer.rs

@@ -2,7 +2,7 @@
 
 use std::sync::MutexGuard;
 
-use proto::{ApprovalAnswer, AuditEvent, DataClass, DenyReason, Timestamp, ToolResponse};
+use bxcore::{ApprovalAnswer, AuditEvent, DataClass, DenyReason, Timestamp, ToolResponse};
 
 use super::{Answer, Answered, Call, Grants, Inner, Ledger};
 use crate::approvals::Verdict;
@@ -107,16 +107,16 @@ impl Ledger {
         guard: &mut MutexGuard<'_, Inner>,
         call: &Call,
         now: Timestamp,
-        status: proto::ResultStatus,
+        status: bxcore::ResultStatus,
         taint_after: DataClass,
         response: &ToolResponse,
     ) -> ToolResponse {
         let (sha256, bytes) = match response {
-            ToolResponse::Result { content, .. } => match proto::sha256(content.as_bytes()) {
+            ToolResponse::Result { content, .. } => match bxcore::sha256(content.as_bytes()) {
                 Ok(sha) => (sha, u64::try_from(content.len()).unwrap_or(u64::MAX)),
                 Err(_) => return Self::not_recorded(),
             },
-            ToolResponse::Failed { message } => match proto::sha256(message.as_bytes()) {
+            ToolResponse::Failed { message } => match bxcore::sha256(message.as_bytes()) {
                 Ok(sha) => (sha, u64::try_from(message.len()).unwrap_or(u64::MAX)),
                 Err(_) => return Self::not_recorded(),
             },
@@ -182,7 +182,7 @@ impl Ledger {
                     &mut guard,
                     call,
                     now,
-                    proto::ResultStatus::Result,
+                    bxcore::ResultStatus::Result,
                     raised.taint,
                     &response,
                 )
@@ -197,7 +197,7 @@ impl Ledger {
                     &mut guard,
                     call,
                     now,
-                    proto::ResultStatus::Failed,
+                    bxcore::ResultStatus::Failed,
                     taint_after,
                     &response,
                 )

crates/brokerd/src/ledger/mod.rs

@@ -6,7 +6,7 @@ mod answer;
 
 use std::sync::{Mutex, MutexGuard};
 
-use proto::{
+use bxcore::{
     AuditEvent, CallId, DataClass, DecisionRecord, DenyReason, GrantProblem, Mode, SessionId,
     Timestamp, ToolRequest, ToolResponse,
 };