fix: make handlerStatus optional to fix TS2741 build errors in DEFAULT_*_ROUTES constants

Agent-Logs-Url: https://github.com/objectstack-ai/spec/sessions/dd6873b1-bdbc-4914-9194-bcdcab8506d1

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

packages/spec/src/api/plugin-rest-api.zod.ts

@@ -169,8 +169,8 @@ export const RestApiEndpointSchema = z.object({
    * - `planned`     – Declared in the protocol spec but not yet implemented.
    * @default 'implemented'
    */
-  handlerStatus: z.enum(['implemented', 'stub', 'planned']).default('implemented')
-    .describe('Handler implementation status: implemented, stub, or planned'),
+  handlerStatus: z.enum(['implemented', 'stub', 'planned']).optional()
+    .describe('Handler implementation status: implemented (default if omitted), stub, or planned'),
 });
 
 export type RestApiEndpoint = z.infer<typeof RestApiEndpointSchema>;