feat: add zalouser channel + directory CLI (#1032) (thanks @suminhthanh)

- Unified UX: channels login + message send; no plugin-specific top-level command\n- Added generic directory CLI for channel identity/groups\n- Docs: channel + plugin pages

extensions/zalouser/src/channel.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from "vitest";
+
+import { zalouserPlugin } from "./channel.js";
+
+describe("zalouser outbound chunker", () => {
+  it("chunks without empty strings and respects limit", () => {
+    const chunker = zalouserPlugin.outbound?.chunker;
+    expect(chunker).toBeTypeOf("function");
+    if (!chunker) return;
+
+    const limit = 10;
+    const chunks = chunker("hello world\nthis is a test", limit);
+    expect(chunks.length).toBeGreaterThan(1);
+    expect(chunks.every((c) => c.length > 0)).toBe(true);
+    expect(chunks.every((c) => c.length <= limit)).toBe(true);
+  });
+});
+