feat: comprehensive debug logging across all controller modules

Add detailed [DEBUG] logging to every controller module when
logging.level is set to "debug". Each module with stateful debug
uses SetDebug(bool) wired from main.go. Covers stacks, backup,
cloudflare, integrations, system, monitor, settings, scheduler,
web handlers, storage, metrics, API, selfupdate, and assets.

Also includes the app export/import (.fab bundles) feature from
v0.32.0 and its debug page integration.

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

controller/internal/scheduler/scheduler.go

@@ -44,12 +44,26 @@ type Scheduler struct {
 	mu      sync.Mutex
 	jobs    []*Job
 	logger  *log.Logger
+	debug   bool
 	ctx     context.Context
 	cancel  context.CancelFunc
 	wg      sync.WaitGroup
 	started bool
 }
 
+// SetDebug enables or disables debug logging.
+func (s *Scheduler) SetDebug(on bool) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.debug = on
+}
+
+func (s *Scheduler) dbg(format string, args ...interface{}) {
+	if s.debug {
+		s.logger.Printf("[DEBUG] [sched] "+format, args...)
+	}
+}
+
 // New creates a new Scheduler.
 func New(logger *log.Logger) *Scheduler {
 	return &Scheduler{
@@ -75,6 +89,7 @@ func (s *Scheduler) Every(name string, interval time.Duration, fn JobFunc) {
 	}
 	s.jobs = append(s.jobs, job)
 	s.logger.Printf("[SCHED] Registered periodic job: %s (every %s)", name, interval)
+	s.dbg("periodic job registered: name=%q interval=%s totalJobs=%d", name, interval, len(s.jobs))
 
 	if s.started {
 		s.wg.Add(1)
@@ -103,6 +118,7 @@ func (s *Scheduler) Daily(name string, timeStr string, fn JobFunc) {
 
 	nextRun := nextDailyRun(timeStr)
 	s.logger.Printf("[SCHED] Daily job %s scheduled for %s", name, nextRun.Format("2006-01-02 15:04 MST"))
+	s.dbg("daily job registered: name=%q schedule=%q nextRun=%s totalJobs=%d", name, timeStr, nextRun.Format(time.RFC3339), len(s.jobs))
 
 	if s.started {
 		s.wg.Add(1)
@@ -132,6 +148,23 @@ func (s *Scheduler) Start(ctx context.Context) {
 	}
 
 	s.logger.Printf("[SCHED] Scheduler started with %d jobs", len(s.jobs))
+	s.dbg("scheduler started: periodic=%d daily=%d", func() int {
+		n := 0
+		for _, j := range s.jobs {
+			if j.Interval > 0 {
+				n++
+			}
+		}
+		return n
+	}(), func() int {
+		n := 0
+		for _, j := range s.jobs {
+			if j.Schedule != "" {
+				n++
+			}
+		}
+		return n
+	}())
 	s.mu.Unlock()
 }
 
@@ -200,10 +233,13 @@ func (s *Scheduler) runDailyJob(job *Job) {
 			waitDuration = 0
 		}
 
+		s.dbg("daily job %s: next run at %s (waiting %s)", job.Name, nextRun.Format("2006-01-02 15:04:05 MST"), waitDuration.Round(time.Second))
+
 		timer := time.NewTimer(waitDuration)
 		select {
 		case <-s.ctx.Done():
 			timer.Stop()
+			s.dbg("daily job %s: context cancelled, stopping", job.Name)
 			return
 		case <-timer.C:
 			s.executeJob(job, false)
@@ -241,6 +277,7 @@ func (s *Scheduler) executeJob(job *Job, quiet bool) {
 	if !quiet {
 		s.logger.Printf("[SCHED] Running job: %s", job.Name)
 	}
+	s.dbg("job %s: execution starting", job.Name)
 
 	start := time.Now()
 	err := job.Fn(s.ctx)
@@ -253,9 +290,11 @@ func (s *Scheduler) executeJob(job *Job, quiet bool) {
 
 	if err != nil {
 		s.logger.Printf("[WARN] Job %s failed: %v (took %s)", job.Name, err, elapsed.Round(time.Millisecond))
+		s.dbg("job %s: failed after %s: %v", job.Name, elapsed.Round(time.Millisecond), err)
 	} else if !quiet {
 		s.logger.Printf("[SCHED] Job %s completed (took %s)", job.Name, elapsed.Round(time.Millisecond))
 	}
+	s.dbg("job %s: finished in %s (err=%v)", job.Name, elapsed.Round(time.Millisecond), err)
 }
 
 // parseDailyTime parses "HH:MM" and returns hour and minute.