v0.4.7: Protected stack detail pages + backup page caching

Task 1: Protected stacks with .felhom.yml (slug) are now clickable
on both dashboard and stacks pages. "Részletek" button added to
protected stack actions section. Filebrowser .felhom.yml updated
with resources metadata.

Task 2: Backup page now reads from a cached FullBackupStatus that
refreshes every 5 minutes in background + after each backup run.
Page loads instantly instead of blocking on restic/docker subprocesses.

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

controller/cmd/controller/main.go

@@ -81,6 +81,11 @@ func main() {
 	var backupMgr *backup.Manager
 	if cfg.Backup.Enabled {
 		backupMgr = backup.NewManager(cfg, pinger, logger)
+		backupMgr.AfterBackup = func() {
+			nextDBDump := scheduler.NextDailyRun(cfg.Backup.DBDumpSchedule)
+			nextBackup := scheduler.NextDailyRun(cfg.Backup.ResticSchedule)
+			backupMgr.RefreshCache(nextDBDump, nextBackup)
+		}
 		go backupMgr.LoadSnapshotHistory()
 	}
 
@@ -120,11 +125,28 @@ func main() {
 		sched.Daily("backup", cfg.Backup.ResticSchedule, func(ctx context.Context) error {
 			return backupMgr.RunBackup(ctx)
 		})
+
+		// Cache refresh: every 5 minutes
+		sched.Every("backup-cache", 5*time.Minute, func(ctx context.Context) error {
+			nextDBDump := scheduler.NextDailyRun(cfg.Backup.DBDumpSchedule)
+			nextBackup := scheduler.NextDailyRun(cfg.Backup.ResticSchedule)
+			backupMgr.RefreshCache(nextDBDump, nextBackup)
+			return nil
+		})
 	}
 
 	sched.Start(ctx)
 	defer sched.Stop()
 
+	// Initial backup cache population (don't block startup)
+	if cfg.Backup.Enabled && backupMgr != nil {
+		go func() {
+			nextDBDump := scheduler.NextDailyRun(cfg.Backup.DBDumpSchedule)
+			nextBackup := scheduler.NextDailyRun(cfg.Backup.ResticSchedule)
+			backupMgr.RefreshCache(nextDBDump, nextBackup)
+		}()
+	}
+
 	// --- Initialize API router ---
 	apiRouter := api.NewRouter(cfg, stackMgr, syncer, cpuCollector, backupMgr, logger)