## Code Analysis

### FOREACH generates a record-target fetch
`server/plpgsql/json.go:642-645`
```go
ForQueryInit{Query: iterateQuery},
ForQueryNext{RecordVar: rowName, GotoOffset: bodySize + 3},
Assignment{VariableName: varName, Expression: rowName + "." + foreachElementField},
```
The generated FOREACH body fetches each array element through `ForQueryNext` as a record, then reads the generated record field into the user loop variable.

### The record-only dispatch is preserved
`server/plpgsql/statements.go:334-340`
```go
// ForQueryNext fetches the next row from the cursor of the scope it runs in and assigns it to either a
// RECORD variable or a list of scalar variables. When the cursor is exhausted it jumps forward by
// GotoOffset (like an If), exiting the loop.
type ForQueryNext struct {
	RecordVar     string
	VariableNames []string
	GotoOffset    int32
}
```

`server/plpgsql/interpreter_logic.go:498-515`
```go
case OpCode_ForQueryNext:
	schema, row, ok := stack.AdvanceCursor()
	if !ok {
		counter = operation.Index - 1
	} else {
		var err error
		if len(operation.SecondaryData) > 0 {
			err = stack.UpdateVariables(ctx, operation.SecondaryData, schema, row)
		} else {
			err = stack.UpdateRecord(operation.Target, schema, row)
		}
		if err != nil {
			return nil, err
		}
	}
```
Because the generated operation has no scalar metadata, it takes the existing `UpdateRecord` branch rather than the scalar-list branch. This supports the report's conclusion that the failing composite-record path is a compatibility defect in the record value/schema handling, not evidence that the scalar dispatch changed this branch.

### The observed cast error is emitted by the return-value conversion path
`server/functions/framework/interpreted_function.go:218-234`
```go
cast, err := castsColl.GetAssignmentCast(ctx, sourceType, targetType)
if err != nil {
	return nil, err
}
if !cast.ID.IsValid() {
	if sourceType.TypCategory == pgtypes.TypeCategory_StringTypes {
		cast.ID = id.NewCast(sourceType.ID, targetType.ID)
		cast.UseInOut = true
	} else {
		return nil, errors.New("no valid cast for return value")
	}
}
return cast.Eval(ctx, val, sourceType, targetType)
```
For the non-string record-shaped value, the missing assignment cast returns the same controlled error captured below before a successful FOREACH result is produced.

## Observed execution

### reproduction request
```sh
docker exec -i <target-container> bash -c 'PGPASSWORD=[REDACTED] psql -h 127.0.0.1 -p 5432 -U postgres -d postgres -v ON_ERROR_STOP=1' <<'SQL'
DROP FUNCTION IF EXISTS qa_foreach_record();
CREATE OR REPLACE FUNCTION qa_foreach_record() RETURNS text AS $$
DECLARE
  r record;
  values_text text := '';
BEGIN
  FOREACH r IN ARRAY ARRAY[ROW(1, 'a'), ROW(2, 'b'), ROW(3, 'c')] LOOP
    values_text := values_text || CASE WHEN values_text = '' THEN '' ELSE ',' END || r.f1 || '/' || r.f2;
  END LOOP;
  RETURN values_text;
END;
$$ LANGUAGE plpgsql;
SELECT qa_foreach_record();
SQL
```

### response
```text
ERROR:  no valid cast for return value
```

The same record-target form that only counts array elements also returned this error during function creation:

```text
ERROR:  no valid cast for return value
```

### result
```text
EXIT_STATUS=3
```

### Test context
The SQL endpoint was reached directly because port 5432 speaks the PostgreSQL wire protocol; the browser `ERR_EMPTY_RESPONSE` was not used as product evidence. The captured record-form output shows the controlled database error before the function could return the expected `1/a,2/b,3/c` fields.

### Result
The runtime evidence and source excerpts support the reported RECORD-2 failure: record-target FOREACH execution returns `no valid cast for return value` instead of completing record assignment and exposing the record fields.