[Max Stegmeyer (mstegmeyer)]

What changed

• Adds a guarded parent admin payments menu entry.
• Adds administration snippets for the menu entry.
• Keeps existing Store routes and menu entries unchanged.
• Skips registration when the module id already exists.
• Does not add ACL registration or navigation privilege.

Testing

• JSON snippets parsed successfully.
• git diff --check passed.
• Administration lint passed with existing warnings only.
• Focused unit spec could not run locally because the trunk administration checkout is missing src/app/mixin/rule-between-operator.mixin.ts before plugin tests start.