feat: recover evolving threads from freeform notes

app/db.py

@@ -604,19 +604,38 @@ class Database:
                     continue
                 seen.add(idea_id)
                 affected.append(idea_id)
-                connection.execute(
-                    """
-                    INSERT OR IGNORE INTO idea_fragments (
-                        idea_id, fragment_id, relevance, created_at
-                    ) VALUES (?, ?, ?, ?)
-                    """,
-                    (
-                        idea_id,
-                        fragment_id,
-                        assessment.get("relevance", 1),
-                        now,
-                    ),
-                )
+                evidence_fragment_ids: list[str] = []
+                for evidence_fragment_id in [
+                    fragment_id,
+                    *assessment.get("supporting_fragment_ids", []),
+                ]:
+                    if evidence_fragment_id in evidence_fragment_ids:
+                        continue
+                    evidence_exists = connection.execute(
+                        """
+                        SELECT 1 FROM fragments
+                        WHERE id = ? AND user_id = ?
+                        """,
+                        (evidence_fragment_id, user_id),
+                    ).fetchone()
+                    if not evidence_exists:
+                        raise ValueError(
+                            "supporting fragment not found for user"
+                        )
+                    evidence_fragment_ids.append(evidence_fragment_id)
+                    connection.execute(
+                        """
+                        INSERT OR IGNORE INTO idea_fragments (
+                            idea_id, fragment_id, relevance, created_at
+                        ) VALUES (?, ?, ?, ?)
+                        """,
+                        (
+                            idea_id,
+                            evidence_fragment_id,
+                            assessment.get("relevance", 1),
+                            now,
+                        ),
+                    )
                 version_state = connection.execute(
                     """
                     SELECT maturity_override FROM ideas