fix(cms): run publish deploy as direct child — detached spawn died under systemd

Root-caused with systemd-run repros: under the unit's hardening flags the
backgrounded grandchild ('cmd &' / setsid) died silently, so a CMS publish
committed+pushed but never rebuilt the site (stale content, no deploy.log,
no trace). A direct (non-detached) exec child provably survives the same
flags; the response is sent first, output goes to deploy.log, and the
callback's audit entry now reports real deploy completion (ok/error).

Closes MITHOME-72

content-editor.js

@@ -305,18 +305,20 @@ const server = http.createServer(async (req, res) => {
       // trigger a rebuild. Deploy only the explicitly configured environment;
       // never default to production. Overridable for tests.
       if (outcome.hadChanges) {
-        // WHY setsid+nohup+stdin-null: under systemd the naive `cmd &` child died
-        // together with the spawning shell (observed: the deploy never ran after a
-        // CMS publish, leaving the site on stale content). Full detachment makes it
-        // survive; the audit entries make the spawn observable instead of silent.
+        // WHY direct child instead of a detached `cmd &`: under the systemd unit's
+        // hardening (NoNewPrivileges/PrivateTmp) the backgrounded grandchild died
+        // silently (observed twice: stale site after a publish). A direct child is
+        // not detached, runs to completion, and the callback turns the audit entry
+        // into a real "deploy finished/failed" signal. The HTTP response is already
+        // sent; deploy output goes to deploy.log so the pipes stay quiet.
         const deployCmd = process.env.CONTENT_EDITOR_DEPLOY_CMD
-          || `cd ../../../ && setsid nohup ./deploy.sh ${CMS_DEPLOY_ENV} > deploy.log 2>&1 < /dev/null &`;
+          || `cd ../../../ && ./deploy.sh ${CMS_DEPLOY_ENV} > deploy.log 2>&1`;
         writeAudit('deploy_spawned', { clientAddress, user: CMS_USER, env: CMS_DEPLOY_ENV });
-        exec(deployCmd, deployError => {
+        exec(deployCmd, { maxBuffer: 8 * 1024 * 1024 }, deployError => {
           writeAudit('deploy_exec_exit', {
             clientAddress,
             user: CMS_USER,
-            result: deployError ? 'error' : 'shell_exited',
+            result: deployError ? 'error' : 'ok',
             error: deployError ? String(deployError.message).slice(0, 300) : undefined,
           });
         });