Schemas: minor updates from the k8s branch (#71688)

Co-authored-by: sam boyer <sdboyer@grafana.com>

kinds/dashboard/dashboard_kind.cue

@@ -17,7 +17,7 @@ lineage: schemas: [{
 		spec: {
 			// Unique numeric identifier for the dashboard.
 			// `id` is internal to a specific Grafana instance. `uid` should be used to identify a dashboard across Grafana instances.
-			id?: int64
+			id?: int64 | null // TODO eliminate this null option
 
 			// Unique dashboard identifier that can be generated by anyone. string (8-40)
 			uid?: string

kinds/preferences/preferences_kind.cue

@@ -27,11 +27,20 @@ lineage: schemas: [{
 
 			// Explore query history preferences
 			queryHistory?: #QueryHistoryPreference
+
+			// Cookie preferences
+			cookiePreferences?: #CookiePreferences
 		} @cuetsy(kind="interface")
 
 		#QueryHistoryPreference: {
 			// one of: '' | 'query' | 'starred';
 			homeTab?: string
 		} @cuetsy(kind="interface")
+
+		#CookiePreferences: {
+			analytics?: {}
+			performance?: {}
+			functional?: {}
+		} @cuetsy(kind="interface")
 	}
 }]