feat: add Services and Logs modules (systemctl + journalctl via SSH)

Backend:
- modules/services: list, status, start/stop/restart systemctl services
  with pct exec support for LXC targets
- modules/logs: journalctl unit listing + WebSocket live streaming
  (direct SSH connection, journalctl -f, graceful teardown on WS close)
- migrations/003: seed services and logs modules in DB
- main.go: register services.New() and logs.New() in module loader

Frontend:
- services.html: target selector, search/filter, services table with
  active state indicators and start/stop/restart buttons
- logs.html: target + unit selectors, live follow toggle, scrollable
  terminal output with 3000-line cap
- app.js: servicePage() and logsPage() Alpine components + navItems
- locales: services and logs i18n keys (fr + en)
- pages.css: services table, state dots, logs output styles

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

frontend/css/pages.css

@@ -826,6 +826,131 @@
 .toast--info    { border-left-color: var(--neu-info);    }
 .toast--info    > i:first-child { color: var(--neu-info); }
 
+/* ── Page Services ───────────────────────────────────────────────────────────── */
+.services-toolbar {
+  display: flex;
+  align-items: center;
+  gap: .75rem;
+  flex-wrap: wrap;
+  margin-bottom: 1rem;
+}
+.services-target-sel { min-width: 12rem; }
+.services-search {
+  display: flex;
+  align-items: center;
+  gap: .5rem;
+  flex: 1;
+  min-width: 10rem;
+  background: var(--neu-bg);
+  border: 1px solid var(--neu-border);
+  border-radius: var(--neu-radius);
+  padding: 0 .75rem;
+}
+.services-search i { color: var(--neu-text-muted); font-size: .9rem; flex-shrink: 0; }
+.services-search .neu-input {
+  border: none;
+  background: transparent;
+  padding: .45rem 0;
+  flex: 1;
+  box-shadow: none;
+  min-width: 0;
+}
+.services-table-wrap { padding: 0; overflow-x: auto; }
+.services-table {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: .875rem;
+}
+.services-table thead tr {
+  border-bottom: 1px solid var(--neu-border);
+}
+.services-table th {
+  padding: .6rem 1rem;
+  text-align: left;
+  font-weight: 600;
+  color: var(--neu-text-muted);
+  white-space: nowrap;
+}
+.services-table td {
+  padding: .5rem 1rem;
+  border-bottom: 1px solid var(--neu-border);
+  vertical-align: middle;
+}
+.services-table tbody tr:last-child td { border-bottom: none; }
+.services-table tbody tr:hover { background: var(--neu-bg-raised); }
+
+.svc-state-dot {
+  display: inline-block;
+  width: .5rem;
+  height: .5rem;
+  border-radius: 50%;
+  margin-right: .4rem;
+  vertical-align: middle;
+}
+.state-active   .svc-state-dot { background: var(--neu-success); }
+.state-failed   .svc-state-dot { background: var(--neu-danger); }
+.state-inactive .svc-state-dot { background: var(--neu-text-muted); }
+.state-other    .svc-state-dot { background: var(--neu-warning); }
+
+.state-active   .svc-state-label { color: var(--neu-success); }
+.state-failed   .svc-state-label { color: var(--neu-danger); }
+.state-inactive .svc-state-label { color: var(--neu-text-muted); }
+
+.svc-name  { font-weight: 500; font-family: var(--neu-font-mono, monospace); white-space: nowrap; }
+.svc-sub   { color: var(--neu-text-muted); font-size: .8rem; white-space: nowrap; }
+.svc-desc  { color: var(--neu-text-muted); font-size: .8rem; max-width: 22rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
+.svc-actions { display: flex; gap: .35rem; white-space: nowrap; }
+
+/* ── Page Logs ───────────────────────────────────────────────────────────────── */
+.logs-toolbar {
+  display: flex;
+  align-items: center;
+  gap: .75rem;
+  flex-wrap: wrap;
+  margin-bottom: 1rem;
+}
+.logs-sel    { min-width: 10rem; }
+.logs-sel-sm { min-width: 5rem; width: 5rem; }
+
+.logs-status {
+  display: flex;
+  align-items: center;
+  gap: .5rem;
+  font-size: .8rem;
+  color: var(--neu-success);
+  margin-bottom: .5rem;
+}
+.logs-status-dot {
+  width: .45rem;
+  height: .45rem;
+  border-radius: 50%;
+  background: var(--neu-success);
+  animation: pulse 1.2s ease-in-out infinite;
+}
+@keyframes pulse {
+  0%, 100% { opacity: 1; }
+  50%       { opacity: .35; }
+}
+
+.logs-output-wrap { padding: 0; min-height: 22rem; display: flex; flex-direction: column; }
+.logs-output {
+  flex: 1;
+  padding: 1rem;
+  margin: 0;
+  font-family: var(--neu-font-mono, 'Courier New', monospace);
+  font-size: .78rem;
+  line-height: 1.5;
+  color: var(--neu-text);
+  overflow-y: auto;
+  max-height: 65vh;
+  white-space: pre-wrap;
+  word-break: break-all;
+}
+.logs-empty {
+  padding: 2rem;
+  text-align: center;
+}
+
 /* ── Éditeur de raccourcis ───────────────────────────────────────────────────── */
 .shortcuts-editor { display: flex; flex-direction: column; gap: .5rem; }
 .shortcut-row {