M3a：息壤三级记忆域——归真触发提取管线/白名单明忆/重忆确认/正影版本链/删除墓碑/双通道召回注入，退役旧记忆-抽取-反思-大周天-演化管线（迁移 004，验收 7 用例）

backend/app/domains/mirror_tree/service.py

@@ -11,6 +11,7 @@
 
 from __future__ import annotations
 
+import asyncio
 import json
 
 from sqlalchemy import select
@@ -413,6 +414,18 @@ async def build_generation_prompt(
         lines.append(f"{speaker}：{expand(n.content)}")
     transcript = "\n".join(lines)
     parts = []
+    # 获准长期记忆（息壤 M3）：召回透明——注入来源可展开，旁枝不入（默认 active 级）
+    if question.tree_id:
+        from app.domains.xirang import service as xirang_service
+
+        recalled = await xirang_service.recall_for_generation(
+            await _tree_character_id(question.tree_id),
+            f"{transcript}\n{question.content}",
+            realm=question.realm,
+        )
+        if recalled:
+            memory_lines = [f"- {m.content}" for m in recalled]
+            parts.append(f"【获准记忆（来源可查）】\n" + "\n".join(memory_lines))
     if transcript:
         parts.append(f"【共同经历（祖先路径）】\n{transcript}")
     parts.append(f"【当前问题】\n{expand(question.content)}")
@@ -730,6 +743,11 @@ async def canonize(
         record_id = record.id
         await session.commit()
 
+    # 息壤：归真产生记忆候选证据（M3）——后台任务，不阻塞归真返回
+    from app.domains.xirang import service as xirang_service
+
+    await xirang_service.on_canonized(record_id)
+
     await one_qi.emit(
         "tree.canonized",
         character_id=tree.character_id,
@@ -873,3 +891,11 @@ async def transplant(
         source="mirror_tree",
     )
     return {"new_tree_id": new_tree_id, "working_entry_node_id": new_entry}
+
+
+async def _tree_character_id(tree_id: str) -> str:
+    from app.models.mirror_tree import MirrorTree
+
+    async with AsyncSessionLocal() as session:
+        tree = await session.get(MirrorTree, tree_id)
+        return tree.character_id if tree else ""