CLI: reduce channels add startup memory (#46784)

* CLI: lazy-load channel subcommand handlers

* Channels: defer add command dependencies

* CLI: skip status JSON plugin preload

* CLI: cover status JSON route preload

* Status: trim JSON security audit path

* Status: update JSON fast-path tests

* CLI: cover root help fast path

* CLI: fast-path root help

* Status: keep JSON security parity

* Status: restore JSON security tests

* CLI: document status plugin preload

* Channels: reuse Telegram account import

src/cli/program/root-help.ts

@@ -0,0 +1,29 @@
+import { Command } from "commander";
+import { VERSION } from "../../version.js";
+import { getCoreCliCommandDescriptors } from "./command-registry.js";
+import { configureProgramHelp } from "./help.js";
+import { getSubCliEntries } from "./register.subclis.js";
+
+function buildRootHelpProgram(): Command {
+  const program = new Command();
+  configureProgramHelp(program, {
+    programVersion: VERSION,
+    channelOptions: [],
+    messageChannelOptions: "",
+    agentChannelOptions: "",
+  });
+
+  for (const command of getCoreCliCommandDescriptors()) {
+    program.command(command.name).description(command.description);
+  }
+  for (const command of getSubCliEntries()) {
+    program.command(command.name).description(command.description);
+  }
+
+  return program;
+}
+
+export function outputRootHelp(): void {
+  const program = buildRootHelpProgram();
+  program.outputHelp();
+}