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

css/style.css

@@ -136,8 +136,9 @@ input:focus, select:focus { border-color:var(--accent); }
 #entriesContainer.table-view th { text-align:left; padding:0.4rem 0.6rem; color:var(--text2); font-size:0.75rem; border-bottom:1px solid var(--border); }
 #entriesContainer.table-view td { padding:0.4rem 0.6rem; font-size:0.8rem; border-bottom:1px solid rgba(255,255,255,0.03); }
 
-.entry-card, .entry-row, .entry-compact, .table-row-drag { cursor:grab; user-select:none; }
+.entry-card, .entry-row, .entry-compact, .table-row-drag { cursor:pointer; user-select:none; }
 .entry-card.drag-over, .entry-row.drag-over, .entry-compact.drag-over, .table-row-drag.drag-over { border-color:var(--accent)!important; box-shadow:0 0 15px rgba(59,130,246,0.3); }
+.entry-card.selected, .entry-row.selected, .entry-compact.selected, .table-row-drag.selected { border-color:var(--accent)!important; box-shadow:0 0 0 2px var(--accent); background:rgba(59,130,246,0.08); }
 .entry-card { background:var(--card); border:1px solid var(--border); border-radius:0.8rem; padding:0.9rem 2.8rem 0.9rem 0.9rem; transition:0.2s; position:relative; word-break:break-word; }
 .entry-card:hover { border-color:rgba(255,255,255,0.15); transform:translateY(-2px); }
 .card-site { font-weight:700; font-size:0.9rem; color:var(--text); margin-bottom:0.2rem; }