datastore: fix flush semantics, upgrade ds9

Author: Thomas Stromberg

pkg/persist/datastore/datastore.go

@@ -261,11 +261,11 @@ func (p *store[K, V]) Cleanup(ctx context.Context, maxAge time.Duration) (int, e
 // Flush removes all entries from Datastore.
 // Returns the number of entries removed and any error.
 func (p *store[K, V]) Flush(ctx context.Context) (int, error) {
-	// Query for all keys
+	// Query for all keys (use empty slice for mock compatibility)
 	query := ds.NewQuery(p.kind).KeysOnly()
 
-	var entries []entry
-	keys, err := p.client.GetAll(ctx, query, &entries)
+	var dst []entry
+	keys, err := p.client.GetAll(ctx, query, &dst)
 	if err != nil {
 		return 0, fmt.Errorf("query all entries: %w", err)
 	}
@@ -285,7 +285,8 @@ func (p *store[K, V]) Flush(ctx context.Context) (int, error) {
 // Len returns the number of entries in Datastore.
 func (p *store[K, V]) Len(ctx context.Context) (int, error) {
 	query := ds.NewQuery(p.kind).KeysOnly()
-	keys, err := p.client.GetAll(ctx, query, nil)
+	var dst []entry
+	keys, err := p.client.GetAll(ctx, query, &dst)
 	if err != nil {
 		return 0, fmt.Errorf("query all entries: %w", err)
 	}

pkg/persist/datastore/go.mod

@@ -3,8 +3,8 @@ module github.com/codeGROOVE-dev/sfcache/pkg/persist/datastore
 go 1.25.4
 
 require (
+	github.com/codeGROOVE-dev/ds9 v0.7.2
 	github.com/codeGROOVE-dev/sfcache/pkg/persist v0.0.0
-	github.com/codeGROOVE-dev/ds9 v0.7.1
 )
 
 replace github.com/codeGROOVE-dev/sfcache/pkg/persist => ..

pkg/persist/datastore/go.sum

@@ -1,2 +1,2 @@
-github.com/codeGROOVE-dev/ds9 v0.7.1 h1:UuffbTksanUPERBkOsiPOe46fkTJlzBOA9jUyfkBxEI=
-github.com/codeGROOVE-dev/ds9 v0.7.1/go.mod h1:0UDipxF1DADfqM5GtjefgB2u+EXdDgOKmxVvrSGLHoM=
+github.com/codeGROOVE-dev/ds9 v0.7.2 h1:Jm+/L/1ACG18lF2SimmgmGu977ocwUebfb2o5AAKeU0=
+github.com/codeGROOVE-dev/ds9 v0.7.2/go.mod h1:0UDipxF1DADfqM5GtjefgB2u+EXdDgOKmxVvrSGLHoM=