Limit archive content upload to single file; improve file section UX

Restrict upload to one file (each archive content item maps to one file);
contextual toggle button text (Switch to Select / Switch to Upload);
swap FontAwesome upload icon for Lucide.

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

src/routes/idaa/(idaa)/archives/[archive_id]/ae_idaa_comp__archive_content_obj_id_edit.svelte

@@ -2,6 +2,7 @@
 // *** Import Svelte core
 import { onMount } from 'svelte';
 import { fade } from 'svelte/transition';
+import * as Lucide from 'lucide-svelte';
 
 // *** Import Aether core variables and functions
 import type { key_val } from '$lib/stores/ae_stores';
@@ -614,7 +615,12 @@ $effect(() => {
                                 }
                             }}>
                             <span class="fas fa-exchange-alt m-1"></span>
-                            Upload/Select
+                            {#if $ae_sess.files.add_to_use_files_method ==
+                                'upload'}
+                                Switch to Select
+                            {:else}
+                                Switch to Upload
+                            {/if}
                         </button>
 
                         <div
@@ -626,6 +632,7 @@ $effect(() => {
                                 link_to_type="archive_content"
                                 link_to_id={$idaa_slct.archive_content_obj
                                     .archive_content_id}
+                                multiple={false}
                                 bind:hosted_file_id_li={hosted_file_id_li_local}
                                 bind:hosted_file_obj_li={hosted_file_obj_li_local}
                                 bind:upload_complete={upload_complete_local}
@@ -633,18 +640,19 @@ $effect(() => {
                                 {#snippet label()}
                                     <div
                                         class="flex flex-col items-center gap-2 py-2">
-                                        <div
+                                        <!-- <div
                                             class="bg-primary-500/10 text-primary-500 rounded-full p-3">
                                             <span class="fas fa-upload fa-lg"
                                             ></span>
-                                        </div>
+                                        </div> -->
                                         <div class="text-center">
                                             <p
                                                 class="text-primary-500 font-bold">
+                                                <Lucide.Upload size="1.25em" class="inline-block mr-1" />
                                                 Upload archive files
                                             </p>
                                             <p class="text-xs opacity-60">
-                                                Recommended: pptx, key, PDF,
+                                                Recommended: pptx, key, pdf,
                                                 mp3, mp4, docx
                                             </p>
                                         </div>