feat(ui): add select all / clear all shortcuts for inbound multi-select (#5175)

* feat(ui): add select all / clear all shortcuts for inbound multi-select

Adds 'Select all' and 'Clear all' buttons above the inbound multi-select in:
- ClientFormModal (add/edit client)
- BulkAttachInboundsModal (bulk attach clients to inbounds)
- BulkDetachInboundsModal (bulk detach clients from inbounds)
- ClientBulkAddModal (add bulk clients)

Extracts the repeated button logic into a reusable SelectAllClearButtons component.

Includes i18n keys for all 13 supported languages with proper translations.

Closes #5144

* refactor(form): decouple SelectAllClearButtons labels and harden select-all

Accept optional selectAllLabel/clearLabel props so the generic form component is not tied to the client-inbound i18n keys (defaults unchanged). Compute the all-selected state by checking every option is present and union the current value on select-all, so it stays correct if value holds ids outside options.

---------

Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>

frontend/src/components/form/SelectAllClearButtons.tsx

@@ -0,0 +1,51 @@
+import { useTranslation } from 'react-i18next';
+import { Button } from 'antd';
+
+interface Option {
+  value: number;
+}
+
+interface SelectAllClearButtonsProps {
+  options: Option[];
+  value: number[];
+  onChange: (value: number[]) => void;
+  /** Override the default "Select all" label (defaults to the inbound copy). */
+  selectAllLabel?: string;
+  /** Override the default "Clear all" label (defaults to the inbound copy). */
+  clearLabel?: string;
+}
+
+export default function SelectAllClearButtons({
+  options,
+  value,
+  onChange,
+  selectAllLabel,
+  clearLabel,
+}: SelectAllClearButtonsProps) {
+  const { t } = useTranslation();
+
+  const optionValues = options.map((o) => o.value);
+  // Treat as "all selected" when every option is chosen, rather than comparing
+  // lengths — this stays correct even if `value` holds ids outside `options`.
+  const allSelected = options.length > 0 && optionValues.every((v) => value.includes(v));
+
+  return (
+    <div style={{ display: 'flex', gap: 8, marginBottom: 8 }}>
+      <Button
+        size="small"
+        disabled={allSelected}
+        // Union with the current value so selections outside `options` are kept.
+        onClick={() => onChange(Array.from(new Set([...value, ...optionValues])))}
+      >
+        {selectAllLabel ?? t('pages.clients.selectAllInbounds')}
+      </Button>
+      <Button
+        size="small"
+        disabled={value.length === 0}
+        onClick={() => onChange([])}
+      >
+        {clearLabel ?? t('pages.clients.clearAllInbounds')}
+      </Button>
+    </div>
+  );
+}

frontend/src/components/form/index.ts

@@ -1,3 +1,4 @@
 export { default as DateTimePicker } from './DateTimePicker';
 export { default as JsonEditor } from './JsonEditor';
 export { default as HeaderMapEditor } from './HeaderMapEditor';
+export { default as SelectAllClearButtons } from './SelectAllClearButtons';