Take a deleted bot out of the rail at once

Deleting a bot only changed the page after a reload. The delete route now
reads who could see the bot before removing it, since its assignments and
workspace places go with it, then pushes server:bot-removed
(BotRemovedData) to them. useLiveBots drops the row, so every tab and
every workspace the bot was in updates together.

src/types/index.ts

@@ -134,6 +134,13 @@ export type BotCreatedData = {
     in_own_chat: boolean;
 };
 
+/**
+ * `server:bot-removed` data: the bot that was deleted.
+ */
+export type BotRemovedData = {
+    bot_id: number;
+};
+
 /**
  * `server:bot-updated` data: the bot's new face and status line, and its
  * active task (null when there is none).
@@ -550,6 +557,10 @@ export const WebSocketEvents = [
      * `BotCreatedData`)
      */
     "server:bot-created",
+    /**
+     * A bot the user could see was deleted (`data`: `BotRemovedData`)
+     */
+    "server:bot-removed",
     /**
      * A bot's face or status line changed (`data`: `BotUpdatedData`)
      */