Remove plans/ directory (P0/P1/P2 work complete)

vfs/predictive/predictive.go

@@ -1,7 +1,7 @@
 package predictive
 
-// Package predictive: experimental / not yet active after P1-04 prune.
-// Retained for potential P2 integration. Not used at runtime (pruned from steamcache).
+// Package predictive: experimental access predictor and prefetch manager.
+// Not active at runtime (pruned from the main request path in earlier hardening work).
 
 import (
 	"context"
@@ -220,7 +220,7 @@ func (ap *AccessPredictor) RecordSequence(previousKey, currentKey string) {
 
 	// Update next keys list (keep top 5)
 	nextKeys := make([]string, 0, 5)
-	for key, _ := range seq.Frequency {
+	for key := range seq.Frequency {
 		nextKeys = append(nextKeys, key)
 		if len(nextKeys) >= 5 {
 			break