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/metrics/logscanner.go

@@ -75,7 +75,7 @@ func ScanContainerLogs(containerNames []string, since time.Duration, logger *log
 	elapsed := time.Since(start)
 	dbg("log scan completed: %d containers in %s", len(containerNames), elapsed.Round(time.Millisecond))
 	if elapsed > 5*time.Minute && logger != nil {
-		logger.Printf("[WARN] Log scan took %s (>5min) for %d containers", elapsed.Round(time.Second), len(containerNames))
+		logger.Printf("[WARN] [metrics] Log scan took %s (>5min) for %d containers", elapsed.Round(time.Second), len(containerNames))
 	}
 
 	return results
@@ -92,7 +92,7 @@ func scanOneContainer(name string, since time.Duration, logger *log.Logger) Cont
 	output, err := cmd.CombinedOutput()
 	if err != nil {
 		if logger != nil {
-			logger.Printf("[DEBUG] logscanner: docker logs %s: %v", name, err)
+			logger.Printf("[DEBUG] [metrics] logscanner: docker logs %s: %v", name, err)
 		}
 		return summary
 	}