fix(errors): never print a blank error for an empty response body

Under heavy load a small fraction of requests (~0.02-0.06%) failed with
an error line that was nothing but ANSI color codes: a dropped
connection or bodyless 5xx produced an empty body, api_error() echoed
it verbatim, and print paths rendered red("") — invisible output with
exit 1.

- util::api_error: empty/whitespace body now falls back to 'unexpected
  empty response from server' (covers every caller, including the
  direct api_error(...).red() prints in databases.rs).
- sdk::format_fail_message: when the body is empty the HTTP status is
  the only signal there is, so surface it: 'error: HTTP 502 Bad Gateway
  (empty response body)'.

Author: eddietejeda

src/client/sdk.rs

@@ -894,6 +894,11 @@ pub fn format_fail_message(
             util::api_error(body.to_string())
         );
     }
+    // An empty body carries no explanation of its own — the status line is
+    // the only signal there is, so surface it instead of a blank message.
+    if body.trim().is_empty() {
+        return format!("error: HTTP {status} (empty response body)");
+    }
     util::api_error(body.to_string())
 }
 
@@ -973,6 +978,18 @@ mod tests {
         assert_eq!(msg, "server exploded");
     }
 
+    #[test]
+    fn format_fail_message_empty_body_surfaces_status() {
+        // An empty response body used to fall through to a blank message
+        // (an error line that was only ANSI color codes). The HTTP status is
+        // the only signal available, so it must appear.
+        let msg = format_fail_message(reqwest::StatusCode::BAD_GATEWAY, "", None);
+        assert_eq!(msg, "error: HTTP 502 Bad Gateway (empty response body)");
+
+        let msg = format_fail_message(reqwest::StatusCode::SERVICE_UNAVAILABLE, " \n", None);
+        assert!(msg.contains("503"), "got: {msg}");
+    }
+
     #[test]
     fn format_fail_message_4xx_connection_error_on_probe_falls_through() {
         let body = r#"{"error":{"message":"forbidden"}}"#;

src/util.rs

@@ -377,6 +377,11 @@ pub fn api_error(body: String) -> String {
     if body.trim_start().starts_with('<') {
         return "unexpected server error".to_string();
     }
+    // A dropped connection or bodyless 5xx yields an empty body; returning it
+    // verbatim would print as a blank (color-codes-only) error line.
+    if body.trim().is_empty() {
+        return "unexpected empty response from server".to_string();
+    }
     body
 }
 
@@ -459,6 +464,20 @@ mod tests {
         assert_eq!(api_error(body), "unexpected server error");
     }
 
+    #[test]
+    fn api_error_never_returns_blank_for_empty_body() {
+        // A dropped connection or bodyless 5xx used to echo the empty body,
+        // printing an error line that was nothing but color codes.
+        assert_eq!(
+            api_error(String::new()),
+            "unexpected empty response from server"
+        );
+        assert_eq!(
+            api_error("  \n".to_string()),
+            "unexpected empty response from server"
+        );
+    }
+
     #[test]
     fn is_access_denied_detects_code() {
         assert!(is_access_denied(