Steer generation rules toward direction pools and readable fills.

Direction-first pools, recipes, and grade manifestation replace enum-tag stuffing; spawned products can be deleted and in-flight runs aborted.

Co-authored-by: Cursor <cursoragent@cursor.com>

web/index.html

@@ -233,7 +233,8 @@
 
     <menu id="flow-node-menu" class="context-menu" hidden>
       <button type="button" class="context-menu-item" id="flow-menu-view" data-flow-menu-action="view">查看产物</button>
-      <button type="button" class="context-menu-item" id="flow-menu-reenter" data-flow-menu-action="reenter">重新进入修改</button>
+      <button type="button" class="context-menu-item" id="flow-menu-reenter" data-flow-menu-action="reenter">进入继续修改</button>
+      <button type="button" class="context-menu-item context-menu-danger context-menu-separator-before" id="flow-menu-delete" data-flow-menu-action="delete">删除产物</button>
     </menu>
 
     <dialog id="dialog-step-artifact" class="dialog dialog-wide" aria-labelledby="step-artifact-title">