Name the analyze goldens stdout.json

The file holds the command's stdout, as stdout.txt did; the extension is
what makes editors highlight it as JSON.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y6XkyWnx7iJFEb8q3AnYps

Author: claude

CLAUDE.md

@@ -120,7 +120,7 @@ A case is a directory holding the inputs and the expected output. `exec.json`
 names the command and its arguments — omit it and the case runs `generate`,
 comparing the generated files against the ones committed alongside; give it
 `{"command": "analyze", "args": [...]}` and the case compares the command's
-stdout against `output.json` (or `stdout.txt` for a command that does not
+stdout against `stdout.json` (or `stdout.txt` for a command that does not
 print JSON). A case that is expected to fail commits its `stderr.txt`. Regenerate a golden by running the command in its directory and
 writing the output back over the committed file.
 

internal/endtoend/case_test.go

@@ -52,11 +52,11 @@ func parseStderr(t *testing.T, dir, testctx string) []byte {
 	return nil
 }
 
-// parseStdout reads the command's expected output: output.json for a
+// parseStdout reads the command's expected output: stdout.json for a
 // command that prints JSON, so editors highlight it, otherwise stdout.txt.
 func parseStdout(t *testing.T, dir string) []byte {
 	t.Helper()
-	for _, name := range []string{"output.json", "stdout.txt"} {
+	for _, name := range []string{"stdout.json", "stdout.txt"} {
 		path := filepath.Join(dir, name)
 		if _, err := os.Stat(path); os.IsNotExist(err) {
 			continue