proxmox-install: build agent binary for serving

The agent binary is never run on the LXC, but it has to be present
so /assets/vetting-agent-linux-amd64 can serve it to target hosts
via the quick-register one-liner. Install was failing because only
orchestrator-linux was being built.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

deploy/proxmox-install.sh

@@ -10,9 +10,14 @@
 #   2. Drops Go into /usr/local/go if a recent enough toolchain isn't
 #      already present.
 #   3. Clones the repo to /opt/vetting-src (or pulls latest if already
-#      there), then `make orchestrator-linux`.
-#   4. Hands off to deploy/install.sh to lay down the binary, the
-#      systemd unit, the example config, and the vetting user.
+#      there), then `make orchestrator-linux agent-linux`. The agent
+#      binary isn't run on the LXC — it's only built so the LXC can
+#      serve it at /assets/vetting-agent-linux-amd64 for target hosts
+#      to fetch via the quick-register one-liner.
+#   4. Hands off to deploy/install.sh to lay down the orchestrator
+#      binary, the agent binary (into /var/lib/vetting/assets for
+#      serving), the systemd unit, the example config, and the
+#      vetting user.
 #
 # Override via env: GO_VERSION, TEMPL_VERSION, SRC_DIR, BRANCH, REPO_URL.
 set -euo pipefail
@@ -69,9 +74,9 @@ fi
 echo "==> installing templ ${TEMPL_VERSION}"
 GOBIN=/usr/local/bin go install "github.com/a-h/templ/cmd/templ@${TEMPL_VERSION}"
 
-echo "==> building orchestrator (make orchestrator-linux)"
+echo "==> building orchestrator + agent (make orchestrator-linux agent-linux)"
 cd "${SRC_DIR}"
-make orchestrator-linux
+make orchestrator-linux agent-linux
 
 echo "==> running deploy/install.sh"
 bash deploy/install.sh --binary "bin/vetting-linux-amd64"
@@ -81,7 +86,7 @@ cat <<EOF
 vetting source is at ${SRC_DIR}.
 
 To upgrade later, rerun this one-liner, or from the source dir:
-    cd ${SRC_DIR} && git pull && make orchestrator-linux \\
+    cd ${SRC_DIR} && git pull && make orchestrator-linux agent-linux \\
         && sudo ./deploy/install.sh --binary bin/vetting-linux-amd64 \\
         && sudo systemctl restart vetting