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/report/builder.go

@@ -34,6 +34,9 @@ func BuildReport(
 	logger *log.Logger,
 ) *Report {
 	debug := cfg.Logging.Level == "debug"
+	if logger != nil {
+		logger.Printf("[INFO] [report] Building system report")
+	}
 	if debug && logger != nil {
 		logger.Printf("[DEBUG] BuildReport: starting — version=%s, storagePaths=%d", version, len(storagePaths))
 	}

controller/internal/report/pusher.go

@@ -125,6 +125,8 @@ func (p *Pusher) Push(report *Report) error {
 		lastErr = fmt.Errorf("HTTP %d", resp.StatusCode)
 	}
 
+	p.logger.Printf("[WARN] [report] Push failed: %v", lastErr)
+
 	p.statusMu.Lock()
 	p.status.LastError = lastErr.Error()
 	p.status.Consecutive++
@@ -186,6 +188,7 @@ func (p *Pusher) PushInfraBackup(data []byte) error {
 		}
 	}
 
+	p.logger.Printf("[WARN] [report] InfraBackup push failed: %v", lastErr)
 	return fmt.Errorf("infra backup push failed after 3 attempts: %w", lastErr)
 }