fix: read-only rich text content overflowing container

Added section-content class with proper ul/ol/li/p margins and
overflow:hidden. Browser defaults for lists were causing content
to extend outside the form input box.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/admin/pages/OfferDetail.tsx

@@ -1099,8 +1099,8 @@ export default function OfferDetail() {
                     <label className="admin-form-label">Obsah</label>
                     {(isInvalidated || isLockedByOther) ? (
                       <div
-                        className="admin-form-input"
-                        style={{ minHeight: '80px', background: 'var(--bg-primary)' }}
+                        className="admin-form-input section-content"
+                        style={{ minHeight: '80px', background: 'var(--bg-primary)', overflow: 'hidden', lineHeight: 1.5, fontSize: '0.875rem' }}
                         dangerouslySetInnerHTML={{ __html: section.content || '<em>Prázdný obsah</em>' }}
                       />
                     ) : (