Add AI follow-up system with call summarization and show history

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_followup.py

@@ -0,0 +1,39 @@
+import sys
+sys.path.insert(0, "/Users/lukemacneil/ai-podcast")
+
+from backend.main import Session, CallRecord, get_caller_prompt
+
+
+def test_caller_prompt_includes_show_history():
+    s = Session()
+    s.call_history.append(CallRecord(
+        caller_type="real", caller_name="Dave",
+        summary="Called about his wife leaving after 12 years",
+        transcript=[],
+    ))
+
+    s.start_call("1")  # Tony
+    caller = s.caller
+    show_history = s.get_show_history()
+    prompt = get_caller_prompt(caller, "", show_history)
+    assert "Dave" in prompt
+    assert "wife leaving" in prompt
+    assert "EARLIER IN THE SHOW" in prompt
+
+
+def test_caller_prompt_without_history():
+    s = Session()
+    s.start_call("1")
+    caller = s.caller
+    prompt = get_caller_prompt(caller, "")
+    assert "EARLIER IN THE SHOW" not in prompt
+    assert caller["name"] in prompt
+
+
+def test_caller_prompt_backward_compatible():
+    """Verify get_caller_prompt works with just 2 args (no show_history)"""
+    s = Session()
+    s.start_call("1")
+    caller = s.caller
+    prompt = get_caller_prompt(caller, "Host: hello")
+    assert "hello" in prompt