Fix isBeforeFirst to return false for empty ResultSet

bindings/java/src/main/java/tech/turso/core/TursoResultSet.java

@@ -104,6 +104,11 @@ public final class TursoResultSet {
     return pastLastRow;
   }
 
+  /** Checks whether the result set is empty (has no rows). */
+  public boolean isEmpty() {
+    return isEmptyResultSet;
+  }
+
   /** Gets the current row number (0-based, 0 means before first row). */
   public int getRow() {
     return row;

bindings/java/src/main/java/tech/turso/jdbc4/JDBC4ResultSet.java

@@ -413,6 +413,10 @@ public final class JDBC4ResultSet implements ResultSet, ResultSetMetaData {
 
   @Override
   public boolean isBeforeFirst() throws SQLException {
+    // Empty ResultSet should return false per JDBC spec
+    if (resultSet.isEmpty()) {
+      return false;
+    }
     return resultSet.isOpen() && resultSet.getRow() == 0 && !resultSet.isPastLastRow();
   }
 

bindings/java/src/test/java/tech/turso/jdbc4/JDBC4ResultSetTest.java

@@ -675,7 +675,8 @@ class JDBC4ResultSetTest {
     ResultSet resultSet = stmt.executeQuery("SELECT * FROM test_empty");
 
     // Before calling next()
-    assertTrue(resultSet.isBeforeFirst());
+    // Empty ResultSet should return false for isBeforeFirst()
+    assertFalse(resultSet.isBeforeFirst());
     assertFalse(resultSet.isAfterLast());
 
     // After calling next() on empty ResultSet