✨ feat(table-copy): 新增整表复制与自动副本命名

- 在表概览及新旧侧栏右键菜单接入复制整表入口与确认、进度和刷新反馈
- 按 source_copyN 原子创建目标表并复制列、索引、默认值及全部数据
- 处理 PostgreSQL 生成列、identity/serial 序列校准与失败清理
- 限定安全数据源与连接保护策略，阻止分区表、RLS 及引用型存储引擎
- 加固 MySQL/PostgreSQL 元数据标识符处理并补齐六语种文案
- 增加后端、能力矩阵、菜单接线和国际化回归测试

internal/db/mariadb_impl.go

@@ -231,12 +231,7 @@ func (m *MariaDB) GetCreateStatement(dbName, tableName string) (string, error) {
 }
 
 func (m *MariaDB) GetColumns(dbName, tableName string) ([]connection.ColumnDefinition, error) {
-	query := fmt.Sprintf("SHOW FULL COLUMNS FROM `%s`.`%s`", dbName, tableName)
-	if dbName == "" {
-		query = fmt.Sprintf("SHOW FULL COLUMNS FROM `%s`", tableName)
-	}
-
-	data, _, err := m.Query(query)
+	data, _, err := m.Query(buildMySQLShowFullColumnsQuery(dbName, tableName))
 	if err != nil {
 		return nil, err
 	}

internal/db/mysql_impl.go

@@ -1071,6 +1071,10 @@ func buildMySQLShowCreateTableQuery(dbName, tableName string) string {
 	return "SHOW CREATE TABLE " + mysqlQualifiedTableIdentifier(dbName, tableName)
 }
 
+func buildMySQLShowFullColumnsQuery(dbName, tableName string) string {
+	return "SHOW FULL COLUMNS FROM " + mysqlQualifiedTableIdentifier(dbName, tableName)
+}
+
 func (m *MySQLDB) GetCreateStatement(dbName, tableName string) (string, error) {
 	data, _, err := m.Query(buildMySQLShowCreateTableQuery(dbName, tableName))
 	if err != nil {
@@ -1086,12 +1090,7 @@ func (m *MySQLDB) GetCreateStatement(dbName, tableName string) (string, error) {
 }
 
 func (m *MySQLDB) GetColumns(dbName, tableName string) ([]connection.ColumnDefinition, error) {
-	query := fmt.Sprintf("SHOW FULL COLUMNS FROM `%s`.`%s`", dbName, tableName)
-	if dbName == "" {
-		query = fmt.Sprintf("SHOW FULL COLUMNS FROM `%s`", tableName)
-	}
-
-	data, _, err := m.Query(query)
+	data, _, err := m.Query(buildMySQLShowFullColumnsQuery(dbName, tableName))
 	if err != nil {
 		return nil, err
 	}

internal/db/mysql_metadata_test.go

@@ -193,3 +193,52 @@ func TestBuildMySQLShowCreateTableQueryNormalizesQuotedIdentifiers(t *testing.T)
 		})
 	}
 }
+
+func TestBuildMySQLShowFullColumnsQueryEscapesIdentifiers(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name      string
+		dbName    string
+		tableName string
+		want      string
+	}{
+		{
+			name:      "plain qualified table",
+			dbName:    "app",
+			tableName: "users",
+			want:      "SHOW FULL COLUMNS FROM `app`.`users`",
+		},
+		{
+			name:      "backticks cannot terminate identifiers",
+			dbName:    "app`prod",
+			tableName: "audit`log",
+			want:      "SHOW FULL COLUMNS FROM `app``prod`.`audit``log`",
+		},
+		{
+			name:      "quoted qualified table overrides database",
+			dbName:    "ignored",
+			tableName: `"sales.region"."daily.order"`,
+			want:      "SHOW FULL COLUMNS FROM `sales.region`.`daily.order`",
+		},
+		{
+			name:      "quoted dotted table remains one identifier",
+			dbName:    "app",
+			tableName: "`audit.logs`",
+			want:      "SHOW FULL COLUMNS FROM `app`.`audit.logs`",
+		},
+		{
+			name:      "table without database",
+			tableName: "standalone",
+			want:      "SHOW FULL COLUMNS FROM `standalone`",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := buildMySQLShowFullColumnsQuery(tt.dbName, tt.tableName); got != tt.want {
+				t.Fatalf("buildMySQLShowFullColumnsQuery(%q,%q)=%q,want=%q", tt.dbName, tt.tableName, got, tt.want)
+			}
+		})
+	}
+}