feat: recover evolving threads from freeform notes

tests/test_db.py

@@ -25,7 +25,11 @@ def database(tmp_path: Path) -> Database:
     return db
 
 
-def assessment(idea_id: str | None = None, maturity: float = 38):
+def assessment(
+    idea_id: str | None = None,
+    maturity: float = 38,
+    supporting_fragment_ids: list[str] | None = None,
+):
     return {
         "idea_id": idea_id,
         "title": "无分类的笔记入口",
@@ -38,6 +42,7 @@ def assessment(idea_id: str | None = None, maturity: float = 38):
         "trajectory": "从输入摩擦的感受，收束成了产品边界。",
         "possible_moves": ["做一个只保留原文的输入原型"],
         "relevance": 1,
+        "supporting_fragment_ids": supporting_fragment_ids or [],
     }
 
 
@@ -119,6 +124,60 @@ def test_curator_prompt_contains_recent_continuity_and_idea_catalog(
     assert "我识别出了两个新的认知" in prompt
     assert "无分类的笔记入口" in prompt
     assert "不要要求用户显式建立会话" in prompt
+    assert "supporting_fragment_ids" in prompt
+    assert "是否形成新的未完成方向" in prompt
+
+
+def test_later_fragment_can_recover_earlier_standalone_evidence(
+    tmp_path: Path,
+):
+    db = database(tmp_path)
+    earlier = db.create_fragment(
+        ADMIN.id, "也许该重新设计小爱的架构，但现在还说不清。"
+    )
+    db.apply_assessments(ADMIN.id, earlier["id"], [])
+    current = db.create_fragment(
+        ADMIN.id, "这个新工作确定要做，我先熟悉 harness 5.0。"
+    )
+
+    db.apply_assessments(
+        ADMIN.id,
+        current["id"],
+        [assessment(supporting_fragment_ids=[earlier["id"]])],
+    )
+
+    idea = db.get_idea(ADMIN.id, db.list_ideas(ADMIN.id)[0]["id"])
+    assert [item["content"] for item in idea["fragments"]] == [
+        earlier["content"],
+        current["content"],
+    ]
+    assert idea["snapshots"][-1]["fragment_ids"] == [
+        earlier["id"],
+        current["id"],
+    ]
+
+
+def test_recovered_evidence_cannot_cross_user_boundary(tmp_path: Path):
+    db = database(tmp_path)
+    member_fragment = db.create_fragment(MEMBER.id, "另一个人的记录")
+    current = db.create_fragment(ADMIN.id, "管理员的新方向")
+
+    try:
+        db.apply_assessments(
+            ADMIN.id,
+            current["id"],
+            [
+                assessment(
+                    supporting_fragment_ids=[member_fragment["id"]]
+                )
+            ],
+        )
+    except ValueError as exc:
+        assert str(exc) == "supporting fragment not found for user"
+    else:
+        raise AssertionError("cross-user supporting fragment was accepted")
+
+    assert db.list_ideas(ADMIN.id) == []
 
 
 def test_delayed_reanalysis_keeps_later_input_out_of_prior_context(