fix(backup): add 5min timeout to tar, fix comment

go/internal/api/routes/admin.go

@@ -2,6 +2,7 @@
 package routes
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -108,15 +109,21 @@ func (aa *AdminAPI) Backup(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// 3. Redis BGSAVE (async)
+	// 3. Redis BGSAVE (fire-and-forget)
 	exec.Command("redis-cli", "BGSAVE").Run()
 
-	// 4. Tar LanceDB directories
-	if err := exec.Command("tar", "czf",
+	// 4. Tar LanceDB directories (5 min timeout — 5.5GB takes ~100s)
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
+	defer cancel()
+	if err := exec.CommandContext(ctx, "tar", "czf",
 		filepath.Join(backupDir, "lance-data.tar.gz"),
 		"-C", dataDir,
 		"episodes.lance", "memories.lance", "tombstones.lance",
 	).Run(); err != nil {
+		if ctx.Err() == context.DeadlineExceeded {
+			respondError(w, 500, "lance backup timed out after 5 minutes")
+			return
+		}
 		respondError(w, 500, "lance backup failed: "+err.Error())
 		return
 	}

go/internal/api/server.go

@@ -930,7 +930,7 @@ func NewServer() http.Handler {
 				case "merge":
 					_, err = consolPipe.RunMerge()
 				case "prune":
-						graphStore.Prune(0.15)
+					graphStore.Prune(0.15)
 				case "decay":
 					// 扫描所有记忆，按衰减率计算 freshness
 					memories, e := ldb.GetCandidatesForForgetting()