fix(table): keep mysql DEFAULT_GENERATED columns copyable

apps/desktop/src/lib/table/tableClipboard.ts

@@ -94,7 +94,9 @@ export function tableDataCopyColumnOptions(databaseType: DatabaseType | undefine
 function isWritableTableDataCopyColumn(databaseType: DatabaseType | undefined, column: ColumnInfo): boolean {
   const extra = (column.extra ?? "").toLowerCase();
   if (databaseType === "mysql") {
-    return !extra.includes("generated");
+    // DEFAULT_GENERATED marks a writable expression default, not a generated column.
+    // Accept both raw EXTRA metadata and the backend's expanded generation clause.
+    return !/\b(?:virtual|stored|persistent)\s+generated\b|\bgenerated\s+always\s+as\s*\(/.test(extra);
   }
   if (databaseType === "postgres") {
     return !extra.includes("generated always as (");

packages/app-tests/tableClipboard.test.ts

@@ -72,8 +72,8 @@ test("table data copy uses only writable columns for first-class databases", ()
     postgresOverridingSystemValue: true,
     sqlserverIdentityInsert: false,
   });
-  assert.deepEqual(tableDataCopyColumnOptions("mysql", [{ ...columns[0], extra: "auto_increment" }, { ...columns[1] }, { ...columns[2], extra: "STORED GENERATED" }]), {
-    columns: ["id", "name"],
+  assert.deepEqual(tableDataCopyColumnOptions("mysql", [{ ...columns[0], extra: "auto_increment" }, { ...columns[1] }, { ...columns[2], extra: "STORED GENERATED" }, column("expr_default", "DEFAULT_GENERATED"), column("expr_default_on_update", "DEFAULT_GENERATED on update CURRENT_TIMESTAMP"), column("virtual_full_name", "VIRTUAL GENERATED"), column("stored_full_name", "GENERATED ALWAYS AS (concat(first_name, ' ', last_name)) STORED")]), {
+    columns: ["id", "name", "expr_default", "expr_default_on_update"],
     postgresOverridingSystemValue: false,
     sqlserverIdentityInsert: false,
   });