feat(conversation): push topic chips after each assistant turn

- Extract maybe_send_topic_chips_ws for WS connect + pipeline reuse
- Default memoir stage to childhood when empty for chip bank lookup
- Resend suggestions after normal assistant reply (English/Chinese)

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

api/app/features/conversation/ws/topic_chips_push.py

@@ -0,0 +1,70 @@
+"""WebSocket 下发话题 chips（opening / resume / 每轮助手回复后）。"""
+
+from datetime import datetime, timezone
+
+from app.agents.chat.prompts_conversation import build_topic_chips
+from app.agents.state_schema import (
+    MemoirStateSchema,
+    interview_control_state,
+    narrative_coverage_state,
+)
+from app.core.config import settings
+from app.core.logging import get_logger
+from app.features.conversation.ws.connection_manager import manager
+from app.features.conversation.ws.message_types import MessageType
+from app.features.conversation.ws.profile_collector import get_missing_profile_fields
+from app.features.user.models import User
+
+log = get_logger(__name__)
+
+
+async def maybe_send_topic_chips_ws(
+    conversation_id: str,
+    *,
+    user: User,
+    memoir_state: MemoirStateSchema,
+    reason: str,
+    language: str,
+) -> None:
+    """资料齐备且开关开启时，按当前回忆录阶段下发 topic_suggestions。失败静默。"""
+    if not settings.chat_topic_chips_enabled:
+        return
+    if get_missing_profile_fields(user):
+        return
+    stage = (memoir_state.current_stage or "").strip() or "childhood"
+    try:
+        narrative_state = narrative_coverage_state(memoir_state)
+        control_state = interview_control_state(memoir_state)
+        empty_slots = control_state.prompt_empty_slots_for_stage(
+            narrative_state, stage
+        )
+        chips = build_topic_chips(
+            stage,
+            empty_slots,
+            max_chips=settings.chat_topic_chips_max,
+            language=language,
+        )
+        if not chips:
+            return
+        await manager.send_message(
+            conversation_id,
+            {
+                "type": MessageType.TOPIC_SUGGESTIONS,
+                "conversation_id": conversation_id,
+                "data": {
+                    "reason": reason,
+                    "stage": stage,
+                    "suggestions": chips,
+                },
+                "timestamp": datetime.now(timezone.utc).isoformat(),
+            },
+        )
+        log.info(
+            "event=ws_topic_chips_sent reason={} conversation_id={} stage={} count={}",
+            reason,
+            conversation_id,
+            stage,
+            len(chips),
+        )
+    except Exception as e:
+        log.warning("发送话题 chips 失败: {}", e)