Replace batch mode toggle with click/Shift/Ctrl selection

- Remove separate 'select mode' toggle and checkbox UI
- Click any entry to select it (blue highlight border)
- Shift+click for range selection between two entries
- Ctrl/Cmd+click to toggle individual entries
- Click entry background or press Escape to clear selection
- Batch action bar appears automatically when items are selected
- Selected entries get accent-color border and highlight
- Single delEntry() cleans up selectedIds
- Shortcut help updated with selection tips

index.html

@@ -155,7 +155,6 @@
                 </div>
                 <div style="display:flex;gap:.4rem;align-items:center;flex-wrap:wrap">
                     <button class="btn btn-outline btn-sm" id="trashBtn" onclick="toggleTrash()" title="Trash">🗑️</button>
-					<button class="btn btn-outline btn-sm" id="selectBtn" onclick="toggleSelectMode()" title="Batch select">☐ Select</button>
 					<button class="btn btn-outline btn-sm" onclick="showShortcutsHelp()" title="Shortcuts">⌨️</button>
                     <div class="view-toggle" id="viewToggle">
                         <button class="view-btn active" data-view="grid">🟫 Grid</button>