refactor(#2581): carve per-agent mcp.sock protocol into hive-agent-sock crate

hive-bash-mcp/Cargo.toml

@@ -8,6 +8,7 @@ workspace = true
 
 [dependencies]
 anyhow.workspace = true
+hive-agent-sock.workspace = true
 hive-sh4re.workspace = true
 libc.workspace = true
 rmcp.workspace = true

hive-bash-mcp/src/runner.rs

@@ -760,7 +760,7 @@ pub(crate) async fn send_wake(
             );
         }
     }
-    let req = hive_sh4re::AgentRequest::Wake {
+    let req = hive_agent_sock::AgentRequest::Wake {
         from: format!("bash-task-{id}"),
         body,
     };