fix(api): lower patch/delete timeout to 20s and add delete auth error banner

Two gaps found during review of the recent retry-hardening commits:

1. api_patch_object.ts and api_delete_object.ts still defaulted to 60s
   timeout while GET/POST were lowered to 20s. No callers set an explicit
   timeout, so the default was the only value used. With retry_count=5 and
   the new backoff policy, 60s per attempt = 5+ minutes worst-case wait.
   Lowered to 20s to match GET/POST and keep worst-case under ~2 minutes.

2. api_delete_object.ts had no ae_auth_error import and no session-expired
   banner on 401/403. A stale-session DELETE would silently return false
   with no user feedback. Added browser + ae_auth_error imports and the
   ae_auth_error.set() call matching the pattern in GET/POST/PATCH.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/ae_api/api_patch_object.ts

@@ -13,7 +13,7 @@ export const patch_object = async function patch_object({
     headers = {},
     params = {},
     data = {},
-    timeout = 60000,
+    timeout = 20000,
     return_meta = false,
     log_lvl = 0,
     retry_count = 5