🐛 fix(oceanbase): 修复 Oracle 协议保存与连接链路

- 测试连接统一走 RPC 配置构造，确保 OceanBase Oracle 协议生效

- 保存连接时同步写入 oceanBaseProtocol 与 protocol 参数

- 编辑回显支持从显式字段、连接参数和 URI 恢复协议

- 双击连接时清理旧树缓存，避免复用 MySQL 协议子节点

- 补充 OceanBase 协议解析与缓存 key 隔离测试

internal/app/methods_db_create_statement_test.go

@@ -90,8 +90,8 @@ func TestResolveDDLDBType_OceanBaseOracleProtocol(t *testing.T) {
 	t.Parallel()
 
 	cfg := connection.ConnectionConfig{
-		Type:             "oceanbase",
-		ConnectionParams: "protocol=oracle",
+		Type:              "oceanbase",
+		OceanBaseProtocol: "oracle",
 	}
 	if got := resolveDDLDBType(cfg); got != "oracle" {
 		t.Fatalf("expected OceanBase Oracle protocol to use oracle DDL dialect, got %q", got)