feat(systemd): unit overview + journal viewer pages

- Add journalctl_recent command and scrum4me-web to whitelist in commands.yml.example
- Add SYSTEMD_UNITS env var to .env.example
- lib/parse-systemd.ts: parse activeState, subState, uptime, description
- /app/systemd: server page reading SYSTEMD_UNITS, client list with 10s polling and status badges
- /app/systemd/[unit]: server detail page, client component showing systemctl status + last 100 journal lines (polling 10s)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ops-agent/commands.yml.example

@@ -37,9 +37,10 @@ commands:
     description: "Fetch all remotes silently (first arg = repo path)"
 
   systemctl_status:
-    cmd: ["systemctl", "status"]
+    cmd: ["systemctl", "status", "--no-pager", "-l"]
     args:
       allowed:
+        - scrum4me-web
         - ops-agent
         - caddy
         - docker
@@ -47,6 +48,18 @@ commands:
         - postgresql
     description: "Show systemctl status for an allowed service"
 
+  journalctl_recent:
+    cmd: ["journalctl", "--since", "1 hour ago", "-n", "100", "--no-pager", "-u"]
+    args:
+      allowed:
+        - scrum4me-web
+        - ops-agent
+        - caddy
+        - docker
+        - nginx
+        - postgresql
+    description: "Last 100 journal lines from the past hour for an allowed service"
+
   caddy_show_config:
     cmd: ["caddy", "fmt", "/etc/caddy/Caddyfile"]
     description: "Print the formatted Caddy config"