v0.6.0: healthcheck + hub reporting implementation

- Add heartbeat ping (every 5 min, controller alive signal)
- Add backup integrity check (weekly restic check, Sunday 04:00)
- Add Heartbeat + BackupIntegrity fields to PingUUIDsConfig
- Add HubConfig for central hub reporting
- Add report package (types, builder, pusher) for hub push
- Wire hub reporting into scheduler (configurable interval)
- Update controller.yaml.example with new monitoring + hub sections
- Add monitoring/DEPRECATED.md for legacy bash scripts

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

controller/internal/backup/backup.go

@@ -270,6 +270,37 @@ func (m *Manager) RunBackup(ctx context.Context) error {
 	return nil
 }
 
+// RunIntegrityCheck runs restic check and pings healthchecks with the result.
+func (m *Manager) RunIntegrityCheck(ctx context.Context) error {
+	m.logger.Printf("[INFO] Starting restic integrity check")
+	start := time.Now()
+
+	if err := m.restic.EnsureInitialized(); err != nil {
+		m.logger.Printf("[ERROR] Restic init failed for integrity check: %v", err)
+		return err
+	}
+
+	err := m.restic.Check()
+	duration := time.Since(start)
+
+	uuid := m.cfg.Monitoring.PingUUIDs.BackupIntegrity
+
+	m.mu.Lock()
+	m.lastCheckTime = time.Now()
+	m.lastCheckOK = err == nil
+	m.mu.Unlock()
+
+	if err != nil {
+		m.logger.Printf("[ERROR] Restic integrity check failed (%s): %v", duration.Round(time.Second), err)
+		m.pinger.Fail(uuid, fmt.Sprintf("restic check failed: %v", err))
+		return err
+	}
+
+	m.logger.Printf("[INFO] Restic integrity check passed (%s)", duration.Round(time.Second))
+	m.pinger.Ping(uuid, fmt.Sprintf("restic check passed (%s)", duration.Round(time.Second)))
+	return nil
+}
+
 // RunFullBackup runs DB dumps followed by restic backup.
 func (m *Manager) RunFullBackup(ctx context.Context) error {
 	m.mu.Lock()