fix: improve sqlite file preview layout and single table handling

- Add min-w-0 to flex containers for proper text truncation
- Use w-max on table to ensure columns don't collapse
- Simplify table selector when only one table exists (remove dropdown)

web/app/components/workflow/skill/viewer/sqlite-file-preview/data-table.tsx

@@ -63,7 +63,7 @@ const DataTable: FC<DataTableProps> = ({ columns, values }) => {
   }, [keyColumnIndex, t, values])
 
   return (
-    <table className="min-w-full table-auto border-separate border-spacing-0">
+    <table className="w-max min-w-full table-auto border-separate border-spacing-0">
       <thead className="sticky top-0 z-10 text-text-secondary">
         <tr>
           {columns.map(column => (