preserve diagnostic context on API, WebSocket, and auth failure paths

src/auth/refresh.ts

@@ -30,8 +30,9 @@ export async function refreshToken(
   });
 
   if (!res.ok) {
+    const body = await res.text().catch(() => '');
     throw new CLIError(
-      `Token refresh failed: ${res.status}`,
+      `Token refresh failed: ${res.status} ${body}`.trim(),
       ExitCode.AUTH,
       'Run `polylane auth login` to re-authenticate'
     );

src/auth/resolver.ts

@@ -19,8 +19,12 @@ export async function resolveCredential(config: Config): Promise<Credential> {
     if (isTokenExpiringSoon(stored)) {
       try {
         return await refreshToken(config, stored);
-      } catch {
-        // Fall through
+      } catch (err) {
+        if (config.verbose) {
+          const msg = err instanceof Error ? err.message : String(err);
+          process.stderr.write(`Token refresh failed: ${msg}
+`);
+        }
       }
     } else {
       return stored;

src/client/http.ts

@@ -133,12 +133,16 @@ export async function requestJson<T>(config: Config, opts: RequestOpts): Promise
   }
 
   let json: ApiEnvelope<T>;
+  let bodyText = '';
   try {
-    json = (await res.json()) as ApiEnvelope<T>;
+    bodyText = await res.text();
+    json = JSON.parse(bodyText) as ApiEnvelope<T>;
   } catch {
+    const snippet = bodyText.slice(0, 500);
     throw new CLIError(
-      `Invalid JSON response from server (status ${res.status})`,
-      ExitCode.GENERAL
+      `Invalid JSON response from ${opts.method ?? 'GET'} ${opts.url} (status ${res.status}): ${snippet}`,
+      ExitCode.GENERAL,
+      `Check --domain=${config.domain} and your network`
     );
   }
 

src/client/thread-chat.ts

@@ -227,12 +227,16 @@ export async function sendThreadMessage(
       rejectOnce(new CLIError(`WebSocket error: ${err.message}`, ExitCode.NETWORK));
     });
 
-    ws.on('close', () => {
+    ws.on('close', (code: number, reason: Buffer) => {
       if (!resolved) {
         if (blockOrder.length > 0) {
           finalize();
         } else {
-          rejectOnce(new CLIError('WebSocket closed before reply', ExitCode.NETWORK));
+          const reasonText = reason.toString('utf-8').trim();
+          rejectOnce(new CLIError(
+            `WebSocket closed before reply (code ${code}${reasonText ? `, ${reasonText}` : ''})`,
+            ExitCode.NETWORK
+          ));
         }
       }
     });