feat(base): floating selection action bar with bulk delete

apps/client/src/features/base/components/grid/grid-container.tsx

@@ -24,6 +24,7 @@ import { useRowDrag } from "@/features/base/hooks/use-row-drag";
 import { GridHeader } from "./grid-header";
 import { GridRow } from "./grid-row";
 import { AddRowButton } from "./add-row-button";
+import { SelectionActionBar } from "./selection-action-bar";
 import classes from "@/features/base/styles/grid.module.css";
 
 const ROW_HEIGHT = 36;
@@ -251,6 +252,7 @@ export function GridContainer({
           )}
 
           <AddRowButton onClick={handleAddRow} />
+          {baseId && <SelectionActionBar baseId={baseId} />}
         </div>
       </div>
     </DndContext>

apps/client/src/features/base/components/grid/selection-action-bar.tsx

@@ -0,0 +1,53 @@
+import { memo } from "react";
+import { ActionIcon, Button, Transition } from "@mantine/core";
+import { IconTrash, IconX } from "@tabler/icons-react";
+import { useTranslation } from "react-i18next";
+import { useRowSelection } from "@/features/base/hooks/use-row-selection";
+import { useDeleteSelectedRows } from "@/features/base/hooks/use-delete-selected-rows";
+import classes from "@/features/base/styles/grid.module.css";
+
+type SelectionActionBarProps = {
+  baseId: string;
+};
+
+export const SelectionActionBar = memo(function SelectionActionBar({
+  baseId,
+}: SelectionActionBarProps) {
+  const { t } = useTranslation();
+  const { selectionCount, clear } = useRowSelection();
+  const { deleteSelected, isPending } = useDeleteSelectedRows(baseId);
+
+  const isOpen = selectionCount > 0;
+
+  return (
+    <Transition mounted={isOpen} transition="slide-up" duration={150}>
+      {(styles) => (
+        <div className={classes.selectionActionBarWrapper} style={styles}>
+          <div className={classes.selectionActionBar}>
+            <span className={classes.selectionActionBarCount}>
+              {t("{{count}} selected", { count: selectionCount })}
+            </span>
+            <Button
+              size="xs"
+              color="red"
+              variant="light"
+              leftSection={<IconTrash size={14} />}
+              loading={isPending}
+              onClick={() => void deleteSelected()}
+            >
+              {t("Delete")}
+            </Button>
+            <ActionIcon
+              size="sm"
+              variant="subtle"
+              onClick={clear}
+              aria-label={t("Clear selection")}
+            >
+              <IconX size={14} />
+            </ActionIcon>
+          </div>
+        </div>
+      )}
+    </Transition>
+  );
+});

apps/client/src/features/base/hooks/use-delete-selected-rows.ts

@@ -0,0 +1,35 @@
+import { useCallback } from "react";
+import { notifications } from "@mantine/notifications";
+import { useTranslation } from "react-i18next";
+import { useRowSelection } from "@/features/base/hooks/use-row-selection";
+import { useDeleteRowsMutation } from "@/features/base/queries/base-row-query";
+
+const BATCH_SIZE = 500;
+
+export function useDeleteSelectedRows(baseId: string) {
+  const { t } = useTranslation();
+  const { selectedIds, clear } = useRowSelection();
+  const mutation = useDeleteRowsMutation();
+
+  const deleteSelected = useCallback(async () => {
+    const ids = Array.from(selectedIds);
+    if (ids.length === 0) return;
+    const chunks: string[][] = [];
+    for (let i = 0; i < ids.length; i += BATCH_SIZE) {
+      chunks.push(ids.slice(i, i + BATCH_SIZE));
+    }
+    try {
+      for (const chunk of chunks) {
+        await mutation.mutateAsync({ baseId, rowIds: chunk });
+      }
+      notifications.show({
+        message: t("{{count}} rows deleted", { count: ids.length }),
+      });
+      clear();
+    } catch {
+      // mutation onError already shows notification
+    }
+  }, [baseId, selectedIds, mutation, clear, t]);
+
+  return { deleteSelected, isPending: mutation.isPending };
+}

apps/client/src/features/base/styles/grid.module.css

@@ -374,3 +374,30 @@
 .hasSelection .rowNumberHeaderCheckbox {
   display: inline-flex;
 }
+
+.selectionActionBarWrapper {
+  position: sticky;
+  bottom: 16px;
+  display: flex;
+  justify-content: center;
+  pointer-events: none;
+  z-index: 5;
+  grid-column: 1 / -1;
+}
+
+.selectionActionBar {
+  pointer-events: auto;
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  padding: 6px 10px;
+  border-radius: var(--mantine-radius-md);
+  box-shadow: var(--mantine-shadow-lg);
+  background: light-dark(var(--mantine-color-white), var(--mantine-color-dark-6));
+  border: 1px solid light-dark(var(--mantine-color-gray-3), var(--mantine-color-dark-4));
+}
+
+.selectionActionBarCount {
+  font-size: var(--mantine-font-size-sm);
+  color: light-dark(var(--mantine-color-gray-7), var(--mantine-color-dark-0));
+}