fix: add customBindHost to gateway config validation (openclaw#20318) thanks @MisterGuy420

Verified:
- pnpm build
- pnpm check
- pnpm test:macmini

Co-authored-by: MisterGuy420 <255743668+MisterGuy420@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

src/config/zod-schema.ts

@@ -404,6 +404,7 @@ export const OpenClawSchema = z
             z.literal("tailnet"),
           ])
           .optional(),
+        customBindHost: z.string().optional(),
         controlUi: z
           .object({
             enabled: z.boolean().optional(),