Share one crew across the install, keep user memory per user

Bots, workspaces and computers now belong to the install. Users reach
workers only through bot_users (assigned by a super admin or admin) and
workspace_users; the coordinator and main computer are one per install,
and only the super admin sees the coordinator. Conversations are per
user (bot_sessions.user_id), jobs run for the session's user, and live
updates go only to who should see them.

A bot's core memory is now general knowledge shared by every user it
works for; what it learns about a user lives in bot_user_memories.

One-off scripts move existing installs over: move-bot-memory-to-owners
(run first), then share-crew.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/layouts/bots/(partials)/rail-add-button.tsx

@@ -1,14 +1,19 @@
 import { useContext } from "react";
 import Button from "@moduletrace/twui/layout/Button";
+import { AppContext } from "@/src/pages/__root";
+import canManageCrew from "@/src/utils/rbac/can-manage-crew";
 import { Plus } from "lucide-react";
 import { AddFlowContext } from "../(data)/add-flow-context";
 
 /**
  * The rail header's Add icon: opens the Add modal (a bot, a workspace or a
- * computer).
+ * computer), for super admins and admins.
  */
 export default function RailAddButton() {
     const { openAdd } = useContext(AddFlowContext);
+    const { pageProps } = useContext(AppContext);
+
+    if (!canManageCrew({ user_types: pageProps?.user_types })) return null;
 
     return (
         <Button