fixes: collab move, caldav abort, draft recovery, autobackup, test stabilization

- Collab: moving a shared card to a local bucket no longer deletes it
  (clear relay_uid before tombstone echo returns)
- CalDAV: abort sync on remote fetch failure instead of treating all
  local cards as remotely-deleted
- Editor: autobackup drafts to localStorage with restore prompt on
  re-open (skipped during tests)
- Cards POST: persist scratchpad and due_date (was dropped on create)
- Disable spellcheck/autocorrect on editor inputs
- Test runner: purge leftover __prefix__ cards/buckets + editor drafts
  before every run (cleans up from failed previous runs)
- Stabilize mark-done, group-delete, undo-body tests with poll loops

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

public/index.php

@@ -250,12 +250,14 @@ if (str_starts_with($route, '/api/')) {
         if ($title === '') { http_response_code(400); echo json_encode(['error' => 'title is required']); exit; }
         $pos = $input['position'] ?? 0;
         $body = $input['body'] ?? '';
-        $db->prepare('INSERT INTO cards (title, body, color, bucket_id, parent_id, position, tags) VALUES (:title, :body, :color, :bucket_id, :parent_id, :position, :tags)')->execute([
+        $db->prepare('INSERT INTO cards (title, body, color, bucket_id, parent_id, position, tags, due_date, scratchpad) VALUES (:title, :body, :color, :bucket_id, :parent_id, :position, :tags, :due_date, :scratchpad)')->execute([
             'title' => $title, 'body' => $body, 'color' => validColor($input['color'] ?? null),
             'bucket_id' => validInt($input['bucket_id'] ?? null, null),
             'parent_id' => validInt($input['parent_id'] ?? null, null),
             'position' => validInt($pos),
             'tags' => extractTags($body),
+            'due_date' => $input['due_date'] ?? null,
+            'scratchpad' => $input['scratchpad'] ?? null,
         ]);
         echo json_encode($db->query('SELECT c.*, b.name as bucket_name FROM cards c LEFT JOIN buckets b ON c.bucket_id = b.id WHERE c.id = ' . $db->lastInsertId())->fetch());
         exit;
@@ -1276,7 +1278,7 @@ if (str_starts_with($route, '/api/')) {
         <div id="quick-capture" class="hidden px-6 py-2 border-t border-t-border bg-t-bg">
             <div class="flex items-center gap-2">
                 <i class="ph ph-lightning text-t-accent text-sm"></i>
-                <input id="quick-capture-input" type="text" placeholder="quick capture — type and press Enter" autocomplete="off" class="flex-1 bg-transparent border-none text-t-bright text-sm focus:outline-none placeholder:text-t-dim font-mono">
+                <input id="quick-capture-input" type="text" placeholder="quick capture — type and press Enter" autocomplete="off" spellcheck="false" autocorrect="off" autocapitalize="off" class="flex-1 bg-transparent border-none text-t-bright text-sm focus:outline-none placeholder:text-t-dim font-mono">
                 <kbd class="text-[9px] text-t-dim border border-t-border rounded px-1 py-0.5 font-pixel">esc</kbd>
             </div>
         </div>
@@ -2195,7 +2197,7 @@ if (str_starts_with($route, '/api/')) {
                 </div>
             </div>
             <div class="flex items-center gap-3 px-4 py-2.5 border-b border-t-border shrink-0">
-                <input type="text" id="inp-title" placeholder="> title..." class="flex-1 bg-transparent border-none text-t-bright text-base font-bold focus:outline-none placeholder:text-t-dim font-pixel">
+                <input type="text" id="inp-title" placeholder="> title..." spellcheck="false" autocorrect="off" autocapitalize="off" class="flex-1 bg-transparent border-none text-t-bright text-base font-bold focus:outline-none placeholder:text-t-dim font-pixel">
                 <button id="inp-due-date" class="flex items-center gap-1 px-2 py-1 text-[10px] font-pixel border border-t-border text-t-dim hover:border-t-accent hover:text-t-accent transition-colors rounded-sm shrink-0" data-tip="set due date">
                     <i class="ph ph-clock-countdown text-xs"></i><span id="inp-due-label">No due</span>
                 </button>
@@ -2260,7 +2262,7 @@ if (str_starts_with($route, '/api/')) {
                     </div>
                     <div class="relative flex-1 min-h-0">
                         <div id="editor-line-hl" class="absolute pointer-events-none left-0 right-0" style="background:var(--t-border);opacity:0.18;display:none;z-index:1;"></div>
-                        <textarea id="editor-body" placeholder="> write markdown..." class="absolute inset-0 w-full h-full text-t-text text-sm font-mono placeholder:text-t-dim border-none overflow-y-auto" style="padding:1rem; line-height:1.625; resize:none; z-index:2; background:transparent;"></textarea>
+                        <textarea id="editor-body" placeholder="> write markdown..." spellcheck="false" autocorrect="off" autocapitalize="off" class="absolute inset-0 w-full h-full text-t-text text-sm font-mono placeholder:text-t-dim border-none overflow-y-auto" style="padding:1rem; line-height:1.625; resize:none; z-index:2; background:transparent;"></textarea>
                     </div>
                 </div>
                 <div id="editor-divider" class="hidden shrink-0" style="width:11px;cursor:col-resize;position:relative;z-index:3;margin:0 -5px;"><div style="position:absolute;left:5px;top:0;bottom:0;width:1px;background:var(--t-border);"></div><div style="position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);width:4px;height:48px;border-radius:2px;background:var(--t-muted);opacity:0.08;transition:opacity 0.2s;"></div></div>
@@ -2271,7 +2273,7 @@ if (str_starts_with($route, '/api/')) {
                         <span class="font-pixel text-[9px] text-t-dim flex-1">scratchpad</span>
                         <button id="scratchpad-clear" class="font-pixel text-[8px] text-t-muted hover:text-t-danger transition-colors">clear</button>
                     </div>
-                    <textarea id="scratchpad-body" placeholder="private notes..." class="flex-1 text-t-muted font-mono placeholder:text-t-dim border-none overflow-y-auto bg-transparent" style="padding:1rem;font-size:11px;line-height:1.625;resize:none;outline:none;"></textarea>
+                    <textarea id="scratchpad-body" placeholder="private notes..." spellcheck="false" autocorrect="off" autocapitalize="off" class="flex-1 text-t-muted font-mono placeholder:text-t-dim border-none overflow-y-auto bg-transparent" style="padding:1rem;font-size:11px;line-height:1.625;resize:none;outline:none;"></textarea>
                 </div>
             </div>
         </div>