feat: 插件更新管理

backend/migration/000004_create_extensions_table.up.sql

@@ -0,0 +1,8 @@
+CREATE TABLE extensions (
+    id UUID PRIMARY KEY DEFAULT uuid_generate_v1(),
+    version VARCHAR(255) NOT NULL,
+    path VARCHAR(1024) NOT NULL,
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE UNIQUE INDEX unique_idx_extensions_version ON extensions(version);