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/setup/setup.go

@@ -101,7 +101,7 @@ func (s *SetupState) SetStep(step string) {
 	s.Step = step
 	s.mu.Unlock()
 	if err := s.Save(); err != nil {
-		log.Printf("[WARN] Failed to save setup step %q: %v", step, err)
+		log.Printf("[WARN] [setup] Failed to save setup step %q: %v", step, err)
 	}
 }