fixes: scratchpad, zen ESC, chat time, tooltip safety, collab sync race

- Scratchpad: card-scoped private notes in editor (toggle vs preview),
  smaller font, cleared via button, stored in cards.scratchpad
- Zen mode: ESC exits zen before closing detail, Z toggles zen
- Chat: always show absolute time (hh:mm, yesterday, or date+time)
- Backspace/Delete also deletes focused card (not just selected)
- Selected + focused cards use brand accent (not accent2)
- Tooltip: guard against non-element targets
- Collab sync: skip poll while editor is open, 2s push debounce
- Rrule test: only check geburtstag tag, not title format

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

public/js/modules/editor.js

@@ -189,12 +189,8 @@ export function openModal(card = null) {
     selectColor(card ? card.color : '#38bdf8');
     setDueDate(card?.due_date || '');
     updateDoneToggle();
-    state.previewVisible = true;
-    preview.classList.remove('hidden');
-    editorDivider?.classList.remove('hidden');
-    $('toggle-preview').classList.add('text-t-accent');
-    applyEditorSplit();
-    updatePreview();
+    if (scratchpadBody) scratchpadBody.value = card?.scratchpad || '';
+    showSidePanel('preview');
     modal.classList.add('open');
     if (linesVisible) updateGutter();
     currentLine = -1;
@@ -396,7 +392,8 @@ function updatePreview() {
 }
 
 async function doSave(close, { animate = true } = {}) {
-    const data = { title: inpTitle.value, body: body.value, color: inpColor.value, bucket_id: inpBucket.value || null, due_date: inpDueValue?.value || null };
+    const scratch = scratchpadBody?.value || null;
+    const data = { title: inpTitle.value, body: body.value, color: inpColor.value, bucket_id: inpBucket.value || null, due_date: inpDueValue?.value || null, scratchpad: scratch };
     if (!data.title.trim()) return;
     const returnToGallery = state.returnToGalleryAfterEdit;
     if (state.editingId) {
@@ -536,18 +533,43 @@ function applyEditorSplit() {
     preview.style.flex = `${100 - editorSplit} 1 0`;
 }
 
-$('toggle-preview')?.addEventListener('click', () => {
-    state.previewVisible = !state.previewVisible;
-    preview.classList.toggle('hidden', !state.previewVisible);
-    editorDivider?.classList.toggle('hidden', !state.previewVisible);
-    $('toggle-preview').classList.toggle('text-t-accent', state.previewVisible);
-    if (state.previewVisible) {
+const scratchpadPanel = $('editor-scratchpad');
+const scratchpadBody = $('scratchpad-body');
+
+function showSidePanel(which) {
+    const showPreview = which === 'preview';
+    const showScratch = which === 'scratchpad';
+
+    state.previewVisible = showPreview;
+    preview.classList.toggle('hidden', !showPreview);
+    scratchpadPanel?.classList.toggle('hidden', !showScratch);
+    editorDivider?.classList.toggle('hidden', !showPreview && !showScratch);
+    $('toggle-preview')?.classList.toggle('text-t-accent', showPreview);
+    $('toggle-scratchpad')?.classList.toggle('text-t-accent', showScratch);
+
+    if (showPreview || showScratch) {
         applyEditorSplit();
+        if (showScratch) scratchpadPanel.style.flex = preview.style.flex || '1 1 0%';
     } else {
         if (editorPane) editorPane.style.flex = '1 1 0%';
         preview.style.flex = '';
+        if (scratchpadPanel) scratchpadPanel.style.flex = '';
     }
-    updatePreview();
+    if (showPreview) updatePreview();
+}
+
+$('toggle-preview')?.addEventListener('click', () => {
+    showSidePanel(state.previewVisible ? null : 'preview');
+});
+
+$('toggle-scratchpad')?.addEventListener('click', () => {
+    const isOpen = !scratchpadPanel?.classList.contains('hidden');
+    showSidePanel(isOpen ? null : 'scratchpad');
+    if (!isOpen) scratchpadBody?.focus();
+});
+
+$('scratchpad-clear')?.addEventListener('click', () => {
+    if (scratchpadBody) scratchpadBody.value = '';
 });
 
 if (editorDivider) {