feat(02-11): secure guardian notification delivery

- Remove record-mutating affordances from Guardian channel payloads\n- Reject managed Telegram callbacks and verify channel attribution

src/__tests__/guardian-notification-payloads.test.ts

@@ -6,23 +6,15 @@ describe("managed Guardian notification payload safety", () => {
   it("recognises only cross-account record delivery as managed Guardian delivery", () => {
     expect(
       isManagedGuardianDelivery({
-        eventType: "MEDICATION_REMINDER",
-        userId: "record-1",
         recordUserId: "record-1",
         recipientUserId: "guardian-1",
-        title: "t",
-        message: "m",
       }),
     ).toBe(true);
 
     expect(
       isManagedGuardianDelivery({
-        eventType: "MEDICATION_REMINDER",
-        userId: "user-1",
         recordUserId: "user-1",
         recipientUserId: "user-1",
-        title: "t",
-        message: "m",
       }),
     ).toBe(false);
   });