fix(tlon): Fix Zod v4 record() and @urbit/aura v3 API changes (#1631)

* fix(tlon): Fix Zod v4 record() and @urbit/aura v3 API changes

- Fix Zod v4.3.6 bug: single-arg z.record() fails with toJSONSchema()
  - Use two-arg form: z.record(z.string(), schema)
  - Fixes 'Cannot read properties of undefined (reading _zod)' error

- Fix @urbit/aura v3.0.0 API migration:
  - unixToDa() → da.fromUnix()
  - formatUd() → scot('ud', ...)
  - Fixes '(0 , _aura.unixToDa) is not a function' error

These were blocking Tlon plugin loading and outbound messaging.

* fix: add tlon schema/aura tests (#1631) (thanks @arthyn)

---------

Co-authored-by: Peter Steinberger <steipete@gmail.com>

extensions/tlon/src/urbit/send.test.ts

@@ -0,0 +1,38 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("@urbit/aura", () => ({
+  scot: vi.fn(() => "mocked-ud"),
+  da: {
+    fromUnix: vi.fn(() => 123n),
+  },
+}));
+
+describe("sendDm", () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it("uses aura v3 helpers for the DM id", async () => {
+    const { sendDm } = await import("./send.js");
+    const aura = await import("@urbit/aura");
+    const scot = vi.mocked(aura.scot);
+    const fromUnix = vi.mocked(aura.da.fromUnix);
+
+    const sentAt = 1_700_000_000_000;
+    vi.spyOn(Date, "now").mockReturnValue(sentAt);
+
+    const poke = vi.fn(async () => ({}));
+
+    const result = await sendDm({
+      api: { poke },
+      fromShip: "~zod",
+      toShip: "~nec",
+      text: "hi",
+    });
+
+    expect(fromUnix).toHaveBeenCalledWith(sentAt);
+    expect(scot).toHaveBeenCalledWith("ud", 123n);
+    expect(poke).toHaveBeenCalledTimes(1);
+    expect(result.messageId).toBe("~zod/mocked-ud");
+  });
+});

extensions/tlon/src/urbit/send.ts

@@ -1,4 +1,4 @@
-import { unixToDa, formatUd } from "@urbit/aura";
+import { scot, da } from "@urbit/aura";
 
 export type TlonPokeApi = {
   poke: (params: { app: string; mark: string; json: unknown }) => Promise<unknown>;
@@ -14,7 +14,7 @@ type SendTextParams = {
 export async function sendDm({ api, fromShip, toShip, text }: SendTextParams) {
   const story = [{ inline: [text] }];
   const sentAt = Date.now();
-  const idUd = formatUd(unixToDa(sentAt));
+  const idUd = scot('ud', da.fromUnix(sentAt));
   const id = `${fromShip}/${idUd}`;
 
   const delta = {