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.ts

@@ -10,7 +10,7 @@ export const TlonChannelRuleSchema = z.object({
 });
 
 export const TlonAuthorizationSchema = z.object({
-  channelRules: z.record(TlonChannelRuleSchema).optional(),
+  channelRules: z.record(z.string(), TlonChannelRuleSchema).optional(),
 });
 
 export const TlonAccountSchema = z.object({
@@ -37,7 +37,7 @@ export const TlonConfigSchema = z.object({
   showModelSignature: z.boolean().optional(),
   authorization: TlonAuthorizationSchema.optional(),
   defaultAuthorizedShips: z.array(ShipSchema).optional(),
-  accounts: z.record(TlonAccountSchema).optional(),
+  accounts: z.record(z.string(), TlonAccountSchema).optional(),
 });
 
 export const tlonChannelConfigSchema = buildChannelConfigSchema(TlonConfigSchema);