feat: comprehensive INFO/WARN/ERROR logging across all controller modules

Add structured operational logging at INFO, WARN, and ERROR levels to
every controller module. Standardize custom prefixes ([GEO], [SCHED],
[SYNC]) to use [INFO/WARN/ERROR] [module] format. Fix misleveled logs
(WARN->ERROR for data loss scenarios, WARN->INFO for routine operations).

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

controller/internal/backup/restore_drives_linux.go

@@ -239,6 +239,7 @@ func mountRawAndBind(ctx context.Context, device string, dm DiskMount, logger *l
 func addDRFstabEntries(dm DiskMount, logger *log.Logger) error {
 	const fstabPath = "/host-fstab"
 
+	logger.Printf("[INFO] [backup] Adding fstab entries for disaster recovery (%s, UUID=%s)", dm.Label, dm.UUID)
 	logger.Printf("[DEBUG] [backup] addDRFstabEntries: checking fstab for %s (UUID=%s)", dm.Label, dm.UUID)
 
 	data, err := os.ReadFile(fstabPath)
@@ -257,20 +258,24 @@ func addDRFstabEntries(dm DiskMount, logger *log.Logger) error {
 	var additions strings.Builder
 	additions.WriteString("\n# Restored by felhom-controller DR\n")
 
+	entryCount := 0
 	if dm.RawMount != "" {
 		// Raw mount entry
 		additions.WriteString(fmt.Sprintf("UUID=%s\t%s\t%s\t%s\t0 2\n",
 			dm.UUID, dm.RawMount, dm.FSType, dm.FstabOptions))
+		entryCount++
 	}
 
 	if dm.BindSubdir != "" && dm.RawMount != "" {
 		// Bind mount entry
 		additions.WriteString(fmt.Sprintf("%s/%s\t%s\tnone\tbind,nofail\t0 0\n",
 			dm.RawMount, dm.BindSubdir, dm.MountPoint))
+		entryCount++
 	} else if dm.RawMount == "" {
 		// Direct mount entry (no bind)
 		additions.WriteString(fmt.Sprintf("UUID=%s\t%s\t%s\t%s\t0 2\n",
 			dm.UUID, dm.MountPoint, dm.FSType, dm.FstabOptions))
+		entryCount++
 	}
 
 	newContent := content + additions.String()
@@ -288,6 +293,7 @@ func addDRFstabEntries(dm DiskMount, logger *log.Logger) error {
 		}
 	}
 
+	logger.Printf("[INFO] [backup] Added %d fstab entries for %s", entryCount, dm.Label)
 	return nil
 }