Prevent autosave exports and preserve raw Markdown

tests/import.php

@@ -244,6 +244,23 @@ try {
     check(Session::get('bluditGithubImport')['args']['username'] === 'spleenftw', 'A valid explicit selection overrides an unavailable repository author');
     echo "PASS: selected/repository authors on create and update, author export, no impersonation or export loop\n";
 
+    // Transient editor snapshots must never enter the public repository.
+    $plugin->requests = [];
+    $pages->add(['slug' => 'autosave-private-snapshot', 'content' => 'private draft', 'type' => 'autosave', 'username' => 'admin']);
+    $plugin->afterPageCreate('autosave-private-snapshot');
+    $plugin->afterPageModify('autosave-private-snapshot');
+    $plugin->afterPageDelete('autosave-private-snapshot');
+    check($plugin->requests === [], 'No GitHub operations for autosave snapshots');
+    $fenced = "```yaml\nfirst: value\n\n  indented: value\n```\n";
+    $plugin->fixture('export-source', document('export-source', $fenced));
+    $plugin->invoke('previewImport', 'export-source', true); $plan = Session::get('bluditGithubImport');
+    $plugin->invoke('confirmImport', $plan['confirmation']);
+    $plugin->requests = [];
+    $plugin->invoke('exportPage', new Page('export-source'));
+    $puts = array_values(array_filter($plugin->requests, function ($r) { return $r[0] === 'PUT'; }));
+    check(count($puts) === 1 && strpos(base64_decode($puts[0][2]['content']), $fenced) !== false, 'Export preserves raw fenced code, not rendered HTML');
+    echo "PASS: no autosave exports and raw Markdown export preserves code fences\n";
+
     // Optional end-to-end fixture using an actual exported article directory.
     if (($articleDir = getenv('BLOG_ARTICLE_DIR'))) {
         $slug = basename(rtrim($articleDir, '/'));