fix: restore tree dropped by 6d224861; land stem95su gdrive-sync (10m) [ci skip]

6d224861 came from a --no-checkout worktree whose empty index made the
commit drop every file except two. This restores 05b50d2b's full tree and
correctly adds stacks/stem95su/gdrive-sync.tf + the service-catalog stem95su
entry. Forward-only (parent=6d224861, no force-push); [ci skip] since the
live infra was never applied from the broken commit.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/t3-serve@.service

@@ -0,0 +1,20 @@
+[Unit]
+Description=T3 Code server for %i (t3 serve, per-user)
+Documentation=https://github.com/pingdotgg/t3code
+After=network.target
+
+[Service]
+Type=simple
+User=%i
+Group=%i
+Environment=HOME=/home/%i
+Environment=PATH=/usr/local/bin:/usr/bin:/bin:/home/%i/.local/bin
+Environment=NODE_ENV=production
+EnvironmentFile=/etc/t3-serve/%i.env
+WorkingDirectory=/home/%i
+ExecStart=/usr/bin/t3 serve --host 0.0.0.0 --port ${T3_PORT} --base-dir /home/%i/.t3
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target