Add a Description field to the Guide information dialog

Reuses the guide's existing descriptionHtml/descriptionText, which
already renders on the PDF cover and at the top of every other export
format, so it surfaces alongside author/co-authors/organization with
no exporter changes needed.

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

app/renderer/dialogs.js

@@ -640,14 +640,19 @@ function showPlaceholdersDialog({ title = 'Placeholders', hint = '', values = {}
 }
 
 /**
- * Optional document metadata (author, co-authors, organization) shown at the
+ * Optional document metadata (author, co-authors, organization, description)
- * top of the guide, below the title, and surfaced on the PDF cover page.
+ * shown at the top of the guide, below the title, and surfaced on the PDF
+ * cover page and the top of other export formats.
  */
 function showGuideInfoDialog({ values = {}, onSave } = {}) {
   return new Promise((resolve) => {
     const authorInput = makeInput(values.author || '', 'text', { placeholder: 'e.g. Jane Doe' });
     const coAuthorsInput = makeInput(values.coAuthors || '', 'text', { placeholder: 'e.g. Alex Lee, Sam Patel' });
     const organizationInput = makeInput(values.organization || '', 'text', { placeholder: 'e.g. Acme Corp' });
+    const descriptionInput = el('textarea', {
+      rows: 4,
+      placeholder: 'A short summary of this guide.',
+    }, values.description || '');
 
     const { close } = openModal({
       title: 'Guide information',
@@ -657,6 +662,9 @@ function showGuideInfoDialog({ values = {}, onSave } = {}) {
         labeledRow('Author', authorInput),
         labeledRow('Co-authors', coAuthorsInput),
         labeledRow('Organization', organizationInput),
+        labeledRow('Description', descriptionInput, { stacked: true }),
+        el('div.muted', { style: { marginTop: '-4px' } },
+          'Shown on the first page of the PDF and at the top of other export formats.'),
       ),
       footer: [
         el('button', { onClick: () => { close(); resolve(false); } }, 'Cancel'),
@@ -666,6 +674,7 @@ function showGuideInfoDialog({ values = {}, onSave } = {}) {
               author: authorInput.value.trim(),
               coAuthors: coAuthorsInput.value.trim(),
               organization: organizationInput.value.trim(),
+              description: descriptionInput.value.trim(),
             });
             close();
             resolve(true);

app/renderer/editor.js

@@ -1574,9 +1574,13 @@ class GuideEditor {
   async openGuideInfo() {
     if (!this.guide) return;
     await dialogs.showGuideInfoDialog({
-      values: this.guide.metadata || {},
+      values: {
-      onSave: async (metadata) => {
+        ...this.guide.metadata,
+        description: htmlToPlainText(this.guide.descriptionHtml || ''),
+      },
+      onSave: async ({ description, ...metadata }) => {
         this.guide.metadata = metadata;
+        this.guide.descriptionHtml = textToHtml(description);
         await api.guide.save({ guide: this.guide });
         this.onToast('Guide information saved.');
       },

app/renderer/util.js

@@ -187,3 +187,21 @@ function fmtDate(iso) {
 
 const escapeHtml = (s) => String(s ?? '')
   .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
+
+/** Inverse of textToHtml, for loading sanitized description HTML into a plain textarea. */
+function htmlToPlainText(html) {
+  return String(html || '')
+    .replace(/<(br|\/p|\/div|\/li|\/h[1-6])\s*\/?>/gi, '\n')
+    .replace(/<[^>]*>/g, '')
+    .replace(/&lt;/g, '<').replace(/&gt;/g, '>').replace(/&quot;/g, '"').replace(/&#39;/g, '\'').replace(/&amp;/g, '&')
+    .replace(/[ \t]+/g, ' ').replace(/\s*\n\s*/g, '\n').trim();
+}
+
+/** Plain textarea text -> sanitizer-allowed paragraph HTML (blank line = new paragraph). */
+function textToHtml(text) {
+  const trimmed = String(text || '').trim();
+  if (!trimmed) return '';
+  return trimmed.split(/\n{2,}/)
+    .map((para) => `<p>${escapeHtml(para).replace(/\n/g, '<br>')}</p>`)
+    .join('');
+}