fix: standardize log prefixes, remove duplicates, add missing module tags

Second-pass logging cleanup: consistent [LEVEL] [module] format across
all 41 files. Remove stale prefixes ([CF], [SYNC], [SCHED], [API],
[STORAGE], [HEALTH], [ROLLBACK]). Remove 5 duplicate log lines. Gate
ungated DEBUG lines. Fix wrong log levels (restore start WARN→INFO).

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

controller/internal/scheduler/scheduler.go

@@ -17,7 +17,7 @@ func getBudapestLocation() *time.Location {
 	budapestLocOnce.Do(func() {
 		loc, err := time.LoadLocation("Europe/Budapest")
 		if err != nil {
-			log.Printf("[ERROR] Cannot load Europe/Budapest timezone: %v — using UTC", err)
+			log.Printf("[ERROR] [scheduler] Cannot load Europe/Budapest timezone: %v — using UTC", err)
 			loc = time.UTC
 		}
 		budapestLoc = loc
@@ -60,7 +60,7 @@ func (s *Scheduler) SetDebug(on bool) {
 
 func (s *Scheduler) dbg(format string, args ...interface{}) {
 	if s.debug {
-		s.logger.Printf("[DEBUG] [sched] "+format, args...)
+		s.logger.Printf("[DEBUG] [scheduler] "+format, args...)
 	}
 }