Add MCP servers and custom tools for bots

Two new settings pages, MCPs and Tools. Super admins define them; super
admins and admins attach them to bots, to workspaces (every bot there),
or to every bot. Bots get them in chat replies and tasks.

- Custom tools: a JSON-schema of arguments plus an HTTP request, a script
  on the bot's computer, or a prompt, templated with {{args.x}} and
  {{env.KEY}}, secrets redacted from results.
- MCP servers: remote (URL and headers) or stdio commands run on the host
  with a setup command and an isolated env, in a per-process pool. Tools
  are listed into a cache and connect on first call.
- Add, edit, access and try open in modals.
- Markdown, JSON and command fields use twui's AceEditor (CodeEditor),
  its scripts loaded on demand.

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

src/dict/settings-pages-dict.ts

@@ -4,10 +4,12 @@ import {
     KeyRound,
     Layers,
     Monitor,
+    Plug,
     Users,
     SlidersHorizontal,
     UserRound,
     Variable,
+    Wrench,
     type LucideIcon,
 } from "lucide-react";
 import type { BUN_SQLITE_COBBLE_USER_TYPES } from "@/db/types/db";
@@ -49,6 +51,8 @@ export const SettingsPages: SettingsPage[] = [
     { title: "Bots", url: "/admin/settings/bots", Icon: Bot, can_view: canManageCrew },
     { title: "Workspaces", url: "/admin/settings/workspaces", Icon: Layers, can_view: canManageCrew },
     { title: "Computers", url: SettingsComputersPath, Icon: Monitor, can_view: canManageCrew },
+    { title: "MCPs", url: "/admin/settings/mcps", Icon: Plug, can_view: canManageCrew },
+    { title: "Tools", url: "/admin/settings/tools", Icon: Wrench, can_view: canManageCrew },
     {
         title: "Users",
         url: "/admin/settings/users",