feat(inbounds): row action to delete all clients of an inbound

Adds POST /panel/api/inbounds/:id/delAllClients that collects every
client email from settings.clients[] and runs ClientService.BulkDelete
in one pass. Row action lives in the More menu as a danger item, only
shown for multi-user inbounds that currently have at least one client;
confirmation modal displays the live client count.

web/translation/en-US.json

@@ -295,6 +295,9 @@
       "resetConfirmContent": "Resets up/down counters to 0 for this inbound.",
       "cloneConfirmTitle": "Clone inbound \"{remark}\"?",
       "cloneConfirmContent": "Creates a copy with a new port and an empty client list.",
+      "delAllClients": "Delete All Clients",
+      "delAllClientsConfirmTitle": "Delete all {count} clients from \"{remark}\"?",
+      "delAllClientsConfirmContent": "This removes every client from this inbound and drops their traffic records. The inbound itself is kept. This cannot be undone.",
       "exportLinksTitle": "Export inbound links",
       "exportSubsTitle": "Export subscription links",
       "exportAllLinksTitle": "Export all inbound links",