feat(auth): extend refresh TTL and keep session on transient errors

Bumps refresh token lifetime to 720h with env overrides, and stops
clearing the local session for non-401 refresh failures so users aren't
logged out by transient network blips. Adds a 60s retry timer when a
refresh fails for non-auth reasons.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/http-client/src/index.ts

@@ -133,8 +133,11 @@ export function createApiClient(options: CreateApiClientOptions = {}): ApiClient
               `Bearer ${nextTokens.accessToken}`;
             return client.request(originalRequest);
           } catch (refreshError) {
-            auth.clearTokens();
-            throw normalizeError(refreshError);
+            const normalizedRefreshError = normalizeError(refreshError);
+            if (normalizedRefreshError.status === 401) {
+              auth.clearTokens();
+            }
+            throw normalizedRefreshError;
           }
         }