feat(api): 支持外部客户端创建作品和更新版本

api/db.ts

@@ -115,6 +115,7 @@ db.exec(`
   );
   CREATE TABLE IF NOT EXISTS notes (
     id INTEGER PRIMARY KEY AUTOINCREMENT,
+    external_id TEXT,
     title TEXT NOT NULL,
     description TEXT NOT NULL DEFAULT '',
     created_at TEXT NOT NULL DEFAULT (datetime('now'))
@@ -196,6 +197,7 @@ function addColumn(table: string, definition: string) {
 }
 
 addColumn('notes', "collection_id INTEGER");
+addColumn('notes', 'external_id TEXT');
 addColumn('notes', "tags TEXT NOT NULL DEFAULT '[]'");
 addColumn('notes', "review_status TEXT NOT NULL DEFAULT 'pending'");
 addColumn('notes', 'version_number INTEGER NOT NULL DEFAULT 1');
@@ -210,6 +212,8 @@ addColumn('images', "storage_key TEXT NOT NULL DEFAULT ''");
 addColumn('images', 'version_number INTEGER NOT NULL DEFAULT 1');
 addColumn('users', 'last_login_at TEXT');
 
+db.exec("CREATE UNIQUE INDEX IF NOT EXISTS idx_notes_collection_external_id ON notes(collection_id, external_id) WHERE external_id IS NOT NULL AND external_id != ''");
+
 const seedGroup = db.prepare('SELECT id FROM operation_groups ORDER BY id LIMIT 1').get() as { id: number } | undefined;
 let groupId = seedGroup?.id;
 if (!groupId) {