Reject unsupported Reddit chat capabilities

tests/conversation-state.test.ts

@@ -4,6 +4,7 @@ import {
   chooseConversationIntent,
   formatConversationAsUntrustedData,
   hybridMediaAskSafetyFailure,
+  conversationReplySafetyFailure,
   mergeConversationState,
   isSafeConversationReply,
   isSafeHybridMediaAsk,
@@ -183,4 +184,11 @@ describe('conversation state', () => {
     expect(isSafeConversationReply('We should meet up sometime.')).toBe(false);
     expect(isSafeConversationReply("I'm 32M in the UK. What kind of music are you into?")).toBe(true);
   });
+
+  it('rejects replies that suggest Reddit chat capabilities the application cannot deliver', () => {
+    expect(conversationReplySafetyFailure('I wish I could send you a voice note right now.'))
+      .toBe('reply suggests an unsupported Reddit chat capability');
+    expect(isSafeConversationReply('Want to hop on a video call?')).toBe(false);
+    expect(isSafeConversationReply('Tell me the rest here, I am listening.')).toBe(true);
+  });
 });