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/utils/check-custom-tool-name.ts

@@ -0,0 +1,28 @@
+import { ReservedToolNames, ReservedToolPrefixes } from "@/src/dict/custom-tool-dict";
+
+type Params = {
+    name: string;
+};
+
+/**
+ * Why a custom tool can't take this name, or null when it can: snake_case
+ * of 2 to 64 characters, never a built-in tool's name or a computer tool's
+ * prefix, and never with `__` (MCP tools use it, `<server>__<tool>`).
+ */
+export default function checkCustomToolName({ name }: Params): string | null {
+    if (!/^[a-z][a-z0-9_]{1,63}$/.test(name)) {
+        return `Use lowercase letters, numbers and underscores, starting with a letter (2 to 64 characters).`;
+    }
+
+    if (name.includes("__")) return `Don't use a double underscore: MCP tools use it.`;
+
+    if ((ReservedToolNames as readonly string[]).includes(name)) {
+        return `${name} is a built-in tool's name.`;
+    }
+
+    const prefix = ReservedToolPrefixes.find((p) => name.startsWith(p));
+
+    if (prefix) return `Names starting with ${prefix} are kept for computers' tools.`;
+
+    return null;
+}