Checkpoint frontend UI/UX overhaul and ingestion embed benchmark work

apps/ai-service/tests/test_conversation.py

@@ -136,6 +136,49 @@ def test_recent_window_evicts_oldest():
     assert state.turn_count == 8
 
 
+def test_evicted_turns_reach_overflow_not_silently_dropped():
+    """Bug fixed 2026-08-06 (Codex review, F-06): `overflow()` used to check
+    `len(self.recent) > window`, but `append()` already truncates `recent`
+    to `window`, so that comparison could never be true — evicted turns
+    never reached the summariser no matter how long a conversation ran.
+    Exact repro from the review: 8 turns into a window of 6."""
+    state = ConversationState("c1")
+    for index in range(8):
+        state = state.append(Turn("user", f"q{index}", "2026-08-05"), window=6)
+
+    overflow = state.overflow()
+
+    assert [turn.text for turn in overflow] == ["q0", "q1"]
+
+
+def test_overflow_accumulates_across_the_two_appends_one_turn_makes():
+    """A live turn typically calls `append()` twice in a row (user, then
+    assistant). Each can evict at most one turn; the second call's overflow
+    must not overwrite, and so lose, the first's."""
+    state = ConversationState("c1")
+    for index in range(6):
+        state = state.append(Turn("user", f"q{index}", "2026-08-05"), window=6)
+    assert state.overflow() == ()  # window exactly full, nothing evicted yet
+
+    state = state.append(Turn("user", "q6", "2026-08-05"), window=6)
+    state = state.append(Turn("assistant", "a6", "2026-08-05"), window=6)
+
+    assert [turn.text for turn in state.overflow()] == ["q0", "q1"]
+
+
+def test_overflow_is_empty_again_after_the_caller_clears_it():
+    from dataclasses import replace
+
+    state = ConversationState("c1")
+    for index in range(8):
+        state = state.append(Turn("user", f"q{index}", "2026-08-05"), window=6)
+    assert state.overflow() != ()
+
+    state = replace(state, pending_overflow=())
+
+    assert state.overflow() == ()
+
+
 def test_focus_update_stamps_the_current_turn():
     state = _state(turn_count=3)