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>

lib/parse-systemd.ts

@@ -0,0 +1,34 @@
+export type ActiveState = 'active' | 'inactive' | 'failed' | 'activating' | 'deactivating' | 'unknown'
+
+export interface UnitStatus {
+  activeState: ActiveState
+  subState: string
+  uptime: string
+  description: string
+}
+
+const KNOWN_STATES = new Set(['active', 'inactive', 'failed', 'activating', 'deactivating'])
+
+export function parseSystemctlStatus(output: string, unitName: string): UnitStatus {
+  let activeState: ActiveState = 'unknown'
+  let subState = ''
+  let uptime = ''
+  let description = unitName
+
+  for (const line of output.split('\n')) {
+    // Header line: "● scrum4me-web.service - Description text"
+    const headerMatch = line.match(/^\s*[●○×◉]\s+\S+\s+-\s+(.+)/)
+    if (headerMatch) description = headerMatch[1].trim()
+
+    // Active line: "     Active: active (running) since Tue 2025-01-13...; 2h 30min ago"
+    const activeMatch = line.match(/\bActive:\s+(\w+)(?:\s+\(([^)]+)\))?(?:.*?;\s+(.+?ago))?/)
+    if (activeMatch) {
+      const state = activeMatch[1].toLowerCase()
+      activeState = KNOWN_STATES.has(state) ? (state as ActiveState) : 'unknown'
+      subState = activeMatch[2] ?? ''
+      uptime = activeMatch[3] ?? ''
+    }
+  }
+
+  return { activeState, subState, uptime, description }
+}