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/config-schema.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, it } from "vitest";
+
+import { TlonAuthorizationSchema, TlonConfigSchema } from "./config-schema.js";
+
+describe("Tlon config schema", () => {
+  it("accepts channelRules with string keys", () => {
+    const parsed = TlonAuthorizationSchema.parse({
+      channelRules: {
+        "chat/~zod/test": {
+          mode: "open",
+          allowedShips: ["~zod"],
+        },
+      },
+    });
+
+    expect(parsed.channelRules?.["chat/~zod/test"]?.mode).toBe("open");
+  });
+
+  it("accepts accounts with string keys", () => {
+    const parsed = TlonConfigSchema.parse({
+      accounts: {
+        primary: {
+          ship: "~zod",
+          url: "https://example.com",
+          code: "code-123",
+        },
+      },
+    });
+
+    expect(parsed.accounts?.primary?.ship).toBe("~zod");
+  });
+});