bxctl: escape error details, time out on admin.sock, AdminError::Io

M3a review findings 9, 10, 12, 13. A retrying error and every error detail
can carry the inference server's body, so they are escaped like model text.
Admin requests wait at most 30 s, so a stuck brokerd cannot hang bxctl or a
chat turn. A failed write is AdminError::Io and stops handle_pending instead
of being answered with another write. The usage line says what audit verify
checks.

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

crates/bxctl/src/chat.rs

@@ -10,7 +10,7 @@ use proto::{
 };
 
 use crate::admin;
-use crate::escape::escape_model_text;
+use crate::escape::{escape_json_text, escape_model_text};
 
 #[derive(Debug)]
 pub enum ChatError {
@@ -25,7 +25,10 @@ impl std::fmt::Display for ChatError {
         match self {
             ChatError::Connect(e) => write!(f, "{e}"),
             ChatError::Frame(e) => write!(f, "{e}"),
-            ChatError::Refused(w) => write!(f, "{}: {}", code_name(w.code), w.detail),
+            // The detail may carry the inference server's body: escape it like model text.
+            ChatError::Refused(w) => {
+                write!(f, "{}: {}", code_name(w.code), escape_json_text(&w.detail))
+            }
             ChatError::Protocol(s) => write!(f, "{s}"),
         }
     }
@@ -188,7 +191,8 @@ impl Printer {
                 self.close_dimmed(out)?;
                 writeln!(
                     out,
-                    "[retrying: attempt {attempt} in {after_ms} ms: {error}]"
+                    "[retrying: attempt {attempt} in {after_ms} ms: {}]",
+                    escape_json_text(error)
                 )?;
             }
             TurnEvent::ThinkingCapped { tokens } => {
@@ -302,6 +306,8 @@ pub fn handle_pending(
     };
     match result {
         Ok(_) => Ok(()),
+        // The output itself failed: writing another line to it would fail the same way.
+        Err(admin::AdminError::Io(e)) => Err(e),
         Err(e) => {
             writeln!(out, "approval {approval}: {e}")?;
             Ok(())