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>

backend/main.go

@@ -17,6 +17,8 @@ import (
 	sshpool "git.geronzi.fr/proxmoxPanel/core/backend/internal/ssh"
 	"git.geronzi.fr/proxmoxPanel/core/backend/internal/websocket"
 	"git.geronzi.fr/proxmoxPanel/core/backend/modules"
+	"git.geronzi.fr/proxmoxPanel/core/backend/modules/logs"
+	"git.geronzi.fr/proxmoxPanel/core/backend/modules/services"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
@@ -68,8 +70,8 @@ func main() {
 
 	// ── Chargement des modules actifs ──────────────────────────────────────
 	loader := modules.NewLoader(database.DB)
-	// Les modules sont enregistrés ici (compilés dans le binaire)
-	// loader.RegisterModule(dashboard.New(...))  ← à décommenter quand implémentés
+	loader.RegisterModule(services.New(database, sshPool, encryptor))
+	loader.RegisterModule(logs.New(database, sshPool, encryptor))
 	if err := loader.LoadActive(); err != nil {
 		log.Fatalf("Erreur chargement modules : %v", err)
 	}