fix(stats): enforce cleanup mode exclusivity and JSON requests

- Reject conflicting explicit cleanup modes
- Require application/json for duplicate-line maintenance requests

launcher/config/cli-parser-builder.ts

@@ -316,14 +316,20 @@ export function parseCliPrograms(
           'Stats --vocab, --lifetime and --duplicate-lines flags require the cleanup action.',
         );
       }
-      if (options.duplicateLines !== true && (options.dryRun === true || options.lookbackDays)) {
+      if (
+        options.duplicateLines !== true &&
+        (options.dryRun === true || options.lookbackDays !== undefined)
+      ) {
         throw new Error('Stats --dry-run and --lookback-days require --duplicate-lines.');
       }
       if (normalizedAction === 'cleanup') {
         statsCleanup = true;
         statsCleanupLifetime = options.lifetime === true;
         statsCleanupDuplicateLines = options.duplicateLines === true;
-        if (statsCleanupLifetime && statsCleanupDuplicateLines) {
+        const explicitModeCount = [options.vocab, options.lifetime, options.duplicateLines].filter(
+          (value) => value === true,
+        ).length;
+        if (explicitModeCount > 1) {
           throw new Error('Stats cleanup runs one mode at a time.');
         }
         // Vocabulary cleanup stays the default so `stats cleanup` keeps its old meaning.

launcher/parse-args.test.ts

@@ -262,13 +262,28 @@ test('parseArgs rejects duplicate-line flags without the duplicate-lines mode',
   assert.match(error.stderr, /--dry-run and --lookback-days require --duplicate-lines/);
 });
 
-test('parseArgs rejects combining lifetime and duplicate-line cleanup modes', () => {
+test('parseArgs rejects an empty lookback value outside duplicate-line cleanup', () => {
   const error = withProcessExitIntercept(() => {
-    parseArgs(['stats', 'cleanup', '--lifetime', '--duplicate-lines'], 'subminer', {});
+    parseArgs(['stats', '--lookback-days', ''], 'subminer', {});
   });
 
   assert.equal(error.code, 1);
-  assert.match(error.stderr, /Stats cleanup runs one mode at a time/);
+  assert.match(error.stderr, /--dry-run and --lookback-days require --duplicate-lines/);
+});
+
+test('parseArgs rejects combining explicit cleanup modes', () => {
+  for (const modes of [
+    ['--lifetime', '--duplicate-lines'],
+    ['--vocab', '--duplicate-lines'],
+    ['--vocab', '--lifetime'],
+  ]) {
+    const error = withProcessExitIntercept(() => {
+      parseArgs(['stats', 'cleanup', ...modes], 'subminer', {});
+    });
+
+    assert.equal(error.code, 1);
+    assert.match(error.stderr, /Stats cleanup runs one mode at a time/);
+  }
 });
 
 test('parseArgs rejects unusable lookback windows', () => {