fix: output OVER clause in rewritten SQL for window functions

The FuncExpr cases in astvisit files were manually constructing
function output but not including the OVER clause, causing
argument-less window functions like ROW_NUMBER() and RANK() to
fail with "misuse of window function" errors.

Author: claude

internal/stackql/astvisit/fragment_rewriting.go

@@ -905,6 +905,9 @@ func (v *standardFragmentRewriteAstVisitor) Visit(node sqlparser.SQLNode) error
 			buf.WriteString(funcName)
 		}
 		buf.AstPrintf(node, "(%s%v)", distinct, node.Exprs)
+		if node.Over != nil {
+			buf.AstPrintf(node, " %v", node.Over)
+		}
 		v.rewrittenQuery = buf.String()
 
 	case *sqlparser.GroupConcatExpr:

internal/stackql/astvisit/from_rewrite.go

@@ -975,6 +975,9 @@ func (v *standardFromRewriteAstVisitor) Visit(node sqlparser.SQLNode) error {
 			buf.WriteString(funcName)
 		}
 		buf.AstPrintf(node, "(%s%v)", distinct, node.Exprs)
+		if node.Over != nil {
+			buf.AstPrintf(node, " %v", node.Over)
+		}
 		v.rewrittenQuery = buf.String()
 
 	case *sqlparser.GroupConcatExpr:

internal/stackql/astvisit/provider_string_extract.go

@@ -904,6 +904,9 @@ func (v *standardProviderStringAstVisitor) Visit(node sqlparser.SQLNode) error {
 			buf.WriteString(funcName)
 		}
 		buf.AstPrintf(node, "(%s%v)", distinct, node.Exprs)
+		if node.Over != nil {
+			buf.AstPrintf(node, " %v", node.Over)
+		}
 		// v.rewrittenQuery = buf.String()
 
 	case *sqlparser.GroupConcatExpr: