fix(files): show legacy file warning banner for trusted-access users

Trusted-access users (Pres Mgmt admins) were getting file_list_status='ready'
when selecting .ppt/.doc/.xls files, so the prominent warning banner never
rendered — only the small per-row warning in the file table was visible.

- element_input_files_tbl: introduce 'warn_legacy' status for trusted users;
  show a yellow warning banner (vs red blocked banner for non-trusted users)
- ae_comp__event_files_upload: change button disabled check from != 'ready'
  to === 'blocked_legacy' so 'warn_legacy' does not accidentally block upload

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

src/lib/elements/element_input_files_tbl.svelte

@@ -280,7 +280,15 @@ async function process_file_list(file_list: FileList) {
     }
 
     const has_blocked = processed_file_list.some((f) => f.block_upload);
-    file_list_status = has_blocked && !$ae_loc.trusted_access ? 'blocked_legacy' : 'ready';
+    // WHY: trusted_access users (Pres Mgmt admins) see a prominent warning but are
+    // not blocked from uploading — they may intentionally handle legacy formats.
+    // Non-trusted users are fully blocked. Both cases get a visible banner; only
+    // the color and button state differ.
+    if (has_blocked) {
+        file_list_status = $ae_loc.trusted_access ? 'warn_legacy' : 'blocked_legacy';
+    } else {
+        file_list_status = 'ready';
+    }
     console.log(processed_file_list);
 
     // return JSON.parse(JSON.stringify(processed_file_list));
@@ -376,6 +384,13 @@ run(() => {
         </div>
     {/if}
 
+    {#if file_list_status == 'warn_legacy'}
+        <div class="m-1 rounded-md border-2 border-yellow-500 bg-yellow-50 p-3 text-sm text-yellow-900 dark:bg-yellow-900/30 dark:text-yellow-200">
+            <strong>⚠ Warning — legacy file format detected.</strong>
+            This Microsoft file type has not been supported in more than 10 years and may not work well. You can still upload, but it is strongly recommended to re-save in the modern format first. See details below.
+        </div>
+    {/if}
+
     <!-- {#await processed_file_list} -->
     <!-- {:then} -->
     {#if use_selected_file_table && processed_file_list && processed_file_list.length}

src/routes/events/ae_comp__event_files_upload.svelte

@@ -279,7 +279,7 @@ async function handle_input_upload_files({
             transition-all
             "
         disabled={$events_sess.files.disable_submit__event_file_obj ||
-            $events_sess.files.status__file_list != 'ready'}>
+            $events_sess.files.status__file_list === 'blocked_legacy'}>
         {#await ae_promises.upload__hosted_file_obj}
             <LoaderCircle class="m-1 animate-spin" />
             <span class="">