fix: resolve multiple 500 errors (#104, #105, #106)

- #104: Add update_chapter_ranges() to StoryNodeRepository
- #105: Fix create_template() database operation in PromptManager
- #106: Fix update_config() database operation in EmbeddingConfigService

All fixes ensure proper connection handling and parameter types.

Author: shenminglinyi

application/ai/embedding_config_service.py

@@ -157,8 +157,9 @@ def update_config(self, **kwargs) -> EmbeddingConfigModel:
         params.append("default")  # WHERE id = ?
 
         sql = f"UPDATE embedding_config SET {', '.join(set_clauses)} WHERE id = ?"
-        db.execute(sql, params)
-        db.get_connection().commit()
+        conn = db.get_connection()
+        conn.execute(sql, tuple(params))
+        conn.commit()
 
         logger.info("EmbeddingConfigService: 配置已更新，字段: %s", list(kwargs.keys()))
         return self.get_config()

infrastructure/ai/prompt_manager.py

@@ -425,13 +425,14 @@ def create_template(self, name: str, description: str = "",
         db = self._get_db()
         tid = _uid()
         now = datetime.now().isoformat()
-        db.execute("""
+        conn = db.get_connection()
+        conn.execute("""
             INSERT INTO prompt_templates
             (id, name, description, category, version, author, icon, color,
              is_builtin, metadata, created_at, updated_at)
             VALUES (?, ?, ?, ?, '1.0.0', '', '📦', '#6b7280', 0, '{}', ?, ?)
         """, (tid, name, description, category, now, now))
-        db.commit()
+        conn.commit()
         return TemplateInfo({"id": tid, "name": name, "description": description,
                              "category": category, "node_count": 0})
 

infrastructure/persistence/database/story_node_repository.py

@@ -417,3 +417,43 @@ def _row_to_entity(self, row: sqlite3.Row) -> StoryNode:
             created_at=datetime.fromisoformat(row_dict["created_at"]),
             updated_at=datetime.fromisoformat(row_dict["updated_at"]),
         )
+
+    async def update_chapter_ranges(self, novel_id: str) -> None:
+        """根据子节点的 chapter_start/chapter_end 更新父节点的章节范围"""
+        conn = self._get_connection()
+        try:
+            cursor = conn.cursor()
+            cursor.execute("""
+                SELECT id, parent_id, chapter_start, chapter_end, node_type
+                FROM story_nodes WHERE novel_id = ?
+                ORDER BY order_index
+            """, (novel_id,))
+            rows = cursor.fetchall()
+
+            nodes_by_parent = {}
+            for row in rows:
+                pid = row[1]
+                if pid not in nodes_by_parent:
+                    nodes_by_parent[pid] = []
+                nodes_by_parent[pid].append(row)
+
+            for parent_id, children in nodes_by_parent.items():
+                if not children:
+                    continue
+                starts = [r[2] for r in children if r[2] is not None]
+                ends = [r[3] for r in children if r[3] is not None]
+                if starts and ends:
+                    new_start = min(starts)
+                    new_end = max(ends)
+                    cursor.execute("""
+                        UPDATE story_nodes
+                        SET chapter_start = ?, chapter_end = ?, updated_at = ?
+                        WHERE id = ?
+                    """, (new_start, new_end, datetime.now().isoformat(), parent_id))
+
+            conn.commit()
+        except Exception as e:
+            conn.rollback()
+            raise e
+        finally:
+            conn.close()