Close a revealed page's open drawer when its back is cancelled

discardOutgoing skipped finished resting edges, so a persistAtRest drawer
opened by a node revealed during a back operation stayed attached after
that back was cancelled and the node returned to history. Found by the
property tests (1000-seed run).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Faarh2Ts6StJPcz2mRiHiR

packages/core-v2/src/scene/graph.ts

@@ -570,7 +570,7 @@ export class SceneGraph {
   }
 
   /**
-   * Resolve the live operations a node started, because the node is leaving
+   * Resolve the operations a node started, because the node is leaving
    * the visible graph: nodes they created (push/replace targets, including
    * replacements whose history skips this node) are removed, and retained
    * entries they revealed (back targets) are restored as if that back
@@ -590,7 +590,7 @@ export class SceneGraph {
 
   private discardOutgoing(nodeKey: string, visited = new Set<string>()): void {
     for (const operation of [...(this.outgoing.get(nodeKey) ?? [])]) {
-      if (operation.phase === "finished") continue;
+      // Includes finished resting edges: an open drawer closes with its page.
       if (operation.history === "back") {
         this.cancel(operation.id);
       } else {