chore(deploy): remove _debug.txt on success; gitignore build output

scripts/deploy-via-docker.js

@@ -247,13 +247,21 @@ async function main() {
 
 main()
   .then(async () => {
+    // On success, keep diagnostics only briefly, then remove the debug file so
+    // it is not left web-served at /userbase/_debug.txt. Failures keep it for
+    // post-mortem (see .catch below).
     await flushDebug();
+    try {
+      if (HELPER_ID) await runExec(HELPER_ID, `rm -f ${HOST_STATIC}/_debug.txt`);
+    } catch (e) {
+      console.error('cleanup debug file failed:', e.message);
+    }
     if (HELPER_ID) await dockerJson('DELETE', `/containers/${HELPER_ID}?force=true`);
     process.exit(0);
   })
   .catch(async (err) => {
     dbg('DEPLOY FAILED: ' + err.stack);
-    await flushDebug();
+    await flushDebug(); // keep debug file on failure for post-mortem
     if (HELPER_ID) await dockerJson('DELETE', `/containers/${HELPER_ID}?force=true`);
     console.error('DEPLOY FAILED:', err.message);
     process.exit(1);