Merge commit e95582a: PR #20 proactive chat, topic chips, low-info turn plan

- Merge staging workflow parent and resolve conflicts with English/i18n and WS pool
- Re-greeting: language-aware fallbacks and prompts; router passes user_language
- RealtimeSession: topic suggestion callbacks + TTS sync path preserved

Co-authored-by: Cursor <cursoragent@cursor.com>

api/tests/test_interview_turn_plan.py

@@ -181,13 +181,66 @@ def test_plan_clarify_first_when_very_short():
     p = plan_interview_turn(
         current_stage="childhood",
         empty_slots=["place"],
-        normalized_user_message="还好吧",
+        normalized_user_message="有点说不清",
         memory_evidence_text="",
         stage_switched_this_turn=False,
     )
     assert p.mode == "clarify_first"
 
 
+def test_plan_low_information_reply_pushes_next_topic_when_slots_remain():
+    p = plan_interview_turn(
+        current_stage="childhood",
+        empty_slots=["place", "people"],
+        normalized_user_message="嗯。",
+        memory_evidence_text="",
+        stage_switched_this_turn=False,
+    )
+    assert p.mode == "memoir_push"
+    assert p.anchor_slot_key == "place"
+    assert p.reply_shape == "ack_then_question"
+    assert p.low_information_reply is True
+
+
+def test_low_information_directive_asks_for_proactive_topic_not_clarification():
+    p = plan_interview_turn(
+        current_stage="childhood",
+        empty_slots=["place"],
+        normalized_user_message="对",
+        memory_evidence_text="",
+        stage_switched_this_turn=False,
+    )
+    block = format_interview_turn_directive_block(p)
+    assert "低信息短回复处理" in block
+    assert "不要把这个短答本身当成需要澄清的内容" in block
+    assert "恰好一个" in block
+    assert "主动" in block
+
+
+def test_plan_low_information_reply_uses_follow_when_no_slots_remain():
+    p = plan_interview_turn(
+        current_stage="childhood",
+        empty_slots=[],
+        normalized_user_message="是的",
+        memory_evidence_text="",
+        stage_switched_this_turn=False,
+    )
+    assert p.mode == "follow_user_only"
+    assert p.reply_shape == "ack_then_question"
+    assert p.low_information_reply is True
+
+
+def test_short_substantive_reply_is_not_treated_as_low_information():
+    p = plan_interview_turn(
+        current_stage="childhood",
+        empty_slots=["place", "people"],
+        normalized_user_message="上海",
+        memory_evidence_text="",
+        stage_switched_this_turn=False,
+    )
+    assert p.low_information_reply is False
+
+
 def test_plan_memoir_push():
     p = plan_interview_turn(
         current_stage="childhood",
@@ -232,3 +285,4 @@ def test_plan_follow_when_no_empty_slots():
         stage_switched_this_turn=False,
     )
     assert p.mode == "follow_user_only"
+    assert p.low_information_reply is True