feat: multi-type file upload with sort order, labels, and expanded MIME support

- DB migration 007: add sort_order + display_label to thesis_files
- Database: getThesisFiles ordered by sort_order; insertThesisFile accepts label/order;
  new reorderThesisFiles() and updateThesisFileLabel() methods
- ThesisCreateController + ThesisEditController: expand allowed MIME/exts to include
  audio (mp3/ogg/wav/flac/aac/m4a), video (webm/mov/ogv), image (gif/webp),
  archives (tar/gz), any-ext via octet-stream; max size raised to 500 MB;
  accept file_labels[] and file_orders[] POST fields; detectFileType() helper
- MediaController: expanded MIME allowlist; HTTP Range support for audio/video;
  force-download for unknown types; inline for known displayable types
- fieldset-files.php: sortable queue UI with SortableJS, per-file labels, 500 MB hint
- templates/admin/edit.php: existing files as sortable list with drag handles,
  type icons, label inputs, delete checkboxes, hidden sort-order fields
- file-upload-queue.js: new JS replacing file-preview.js — sortable new-file queue,
  per-file labels, hidden order fields on submit, backward-compat legacy preview
- tfe.php: renders audio (<audio>), all video formats, images, PDF, and
  download-only 'other' files; reads display_label; sorted by sort_order
- tfe.css + form.css: styles for audio player, download files, sortable queue,
  drag handles, file type badges, label inputs
- .htaccess + .user.ini: upload_max_filesize=512M / post_max_size=520M

app/public/assets/css/tfe.css

@@ -151,6 +151,53 @@ aside figcaption {
     margin: var(--space-3xs) 0 0;
 }
 
+/* Audio player */
+.tfe-audio {
+    width: 100%;
+    margin: 0;
+    display: block;
+}
+
+/* Download-only files */
+.tfe-download-file {
+    display: flex;
+    align-items: center;
+    gap: var(--space-xs);
+    padding: var(--space-s) var(--space-m);
+    background: var(--bg-secondary);
+    border: 1px solid var(--border-primary);
+    border-radius: 6px;
+    flex-wrap: wrap;
+}
+
+.tfe-download-link {
+    display: flex;
+    align-items: center;
+    gap: var(--space-xs);
+    font-size: var(--step--1);
+    font-weight: 500;
+    color: var(--text-primary);
+    text-decoration: underline;
+    text-underline-offset: 2px;
+    word-break: break-all;
+}
+
+.tfe-download-link:hover {
+    color: var(--accent-primary);
+}
+
+.tfe-download-icon {
+    font-size: 1.3rem;
+    line-height: 1;
+    flex-shrink: 0;
+}
+
+.tfe-download-size {
+    font-size: var(--step--2);
+    color: var(--text-tertiary);
+    margin-left: auto;
+}
+
 .tfe-pdf-fallback a {
     color: var(--text-primary);
     text-decoration: underline;