feat: add "Copy as SQL ALTER" to DataGrid column header context menu

Right-click a column header in the data grid to copy the ALTER TABLE
statement for that column, making it easy to replicate column definitions
across databases. Supports all major dialects (MySQL, Postgres, SQL Server,
Oracle, ClickHouse, SQLite, DuckDB, H2).

Closes #516

src-tauri/src/commands/query.rs

@@ -352,6 +352,13 @@ pub fn build_create_table_sql(
     Ok(dbx_core::table_structure_sql::build_create_table_sql(options))
 }
 
+#[tauri::command]
+pub fn build_single_column_alter_sql(
+    options: dbx_core::table_structure_sql::SingleColumnAlterSqlOptions,
+) -> Result<dbx_core::table_structure_sql::TableStructureSqlResult, String> {
+    Ok(dbx_core::table_structure_sql::build_single_column_alter_sql(options))
+}
+
 #[tauri::command]
 pub fn analyze_editable_query_editability(sql: String) -> Result<dbx_core::sql_editability::QueryEditability, String> {
     Ok(dbx_core::sql_editability::analyze_editable_query_editability(&sql))