test: enhance deep link testing with real JWT examples

Changes:
- Add real JWT example for invite testing
- Add detailed JWT payload documentation
- Update test-deeplinks.sh with valid claim IDs
- Add test case for single contact invite
- Improve test descriptions and organization

This improves test coverage by using real-world JWT examples
and valid claim identifiers.

src/interfaces/records.ts

@@ -58,6 +58,7 @@ export interface PlanSummaryRecord {
   name?: string;
   startTime?: string;
   url?: string;
+  jwtId?: string;
 }
 
 /**