refactor(shared): reuse outbound text chunking core

src/plugin-sdk/text-chunking.test.ts

@@ -0,0 +1,16 @@
+import { describe, expect, it } from "vitest";
+import { chunkTextForOutbound } from "./text-chunking.js";
+
+describe("chunkTextForOutbound", () => {
+  it("returns empty for empty input", () => {
+    expect(chunkTextForOutbound("", 10)).toEqual([]);
+  });
+
+  it("splits on newline or whitespace boundaries", () => {
+    expect(chunkTextForOutbound("alpha\nbeta gamma", 8)).toEqual(["alpha", "beta", "gamma"]);
+  });
+
+  it("falls back to hard limit when no separator exists", () => {
+    expect(chunkTextForOutbound("abcdefghij", 4)).toEqual(["abcd", "efgh", "ij"]);
+  });
+});