fix(i18n): replace raw translation keys on panel screens (#7057)

Use valid translation keys on six panel screens, add the missing copy-failure and empty-value strings across all locales, and reject unresolved literal translation keys in the regression test.

frontend/src/pages/clients/ClientBulkAdjustModal.tsx

@@ -95,7 +95,7 @@ export default function ClientBulkAdjustModal({
       <Modal
         open={open}
         title={t('pages.clients.bulkAdjustTitle', { count })}
-        okText={t('apply')}
+        okText={t('confirm')}
         cancelText={t('cancel')}
         confirmLoading={submitting}
         onOk={handleOk}

frontend/src/pages/clients/FilterDrawer.tsx

@@ -128,7 +128,7 @@ export default function FilterDrawer({
           />
         </Form.Item>
 
-        <Form.Item label={t('inbounds')} htmlFor={`${uid}-inbounds`}>
+        <Form.Item label={t('pages.clients.attachedInbounds')} htmlFor={`${uid}-inbounds`}>
           <Select
             id={`${uid}-inbounds`}
             mode="multiple"
@@ -136,7 +136,7 @@ export default function FilterDrawer({
             value={filters.inboundIds}
             onChange={(v) => patch('inboundIds', v as number[])}
             options={inboundOptions}
-            placeholder={t('inbounds')}
+            placeholder={t('pages.clients.attachedInbounds')}
             allowClear
             showSearch={{ optionFilterProp: 'label' }}
             listHeight={220}