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.go

@@ -87,7 +87,7 @@ func (m *Manager) RestoreApp(stackName, snapshotID string) error {
 		m.logger.Printf("[DEBUG] RestoreApp: using repo=%s, %d restore path(s)", repoPath, len(restorePaths))
 	}
 
-	m.logger.Printf("[WARN] RESTORE starting: stack=%s, snapshot=%s, repo=%s, paths=%v, hasHDD=%v",
+	m.logger.Printf("[INFO] [backup] Starting restore for %s (snapshot=%s, repo=%s, paths=%v, hasHDD=%v)",
 		stackName, snapshotID, repoPath, restorePaths, hasHDD)
 
 	// Stop the app before restore