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/stacks/delete.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"context"
 	"fmt"
+	"log"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -557,6 +558,7 @@ func ParseComposeHDDMounts(composePath, hddPath string) []string {
 		}
 	}
 
+	log.Printf("[INFO] [stacks] ParseComposeHDDMounts: found %d HDD mounts for %s", len(mounts), composePath)
 	return mounts
 }