fix: DGET multiple-match check takes priority over field CellError

The defensive CellError guard added earlier returned the error as soon
as a matching row with a field error was seen, even when more rows
also matched. Excel's DGET resolves the "multiple matches → #NUM!"
check first and only surfaces field errors when exactly one record
matches.

Move the CellError check to after the loop so the match count is
finalised first. Addresses Cursor Bugbot finding.

Regression tests added in hyperformula-tests.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: marcin-kordas-hoc

src/interpreter/plugin/DatabasePlugin.ts

@@ -237,22 +237,22 @@ export class DatabasePlugin extends FunctionPlugin implements FunctionPluginType
 
       for (let rowIdx = 1; rowIdx < dbData.length; rowIdx++) {
         if (this.rowMatchesCriteria(dbData[rowIdx], criteriaRows)) {
-          const cellValue = dbData[rowIdx][fieldIndex]
-          if (cellValue instanceof CellError) {
-            return cellValue
-          }
           matchCount++
           if (matchCount > 1) {
             return new CellError(ErrorType.NUM, ErrorMessage.ValueLarge)
           }
-          matchedValue = cellValue
+          matchedValue = dbData[rowIdx][fieldIndex]
         }
       }
 
       if (matchCount === 0) {
         return new CellError(ErrorType.VALUE, ErrorMessage.WrongType)
       }
 
+      if (matchedValue instanceof CellError) {
+        return matchedValue
+      }
+
       return matchedValue === EmptyValue || matchedValue === undefined || matchedValue === null
         ? 0
         : matchedValue