This will be available in the next version.
Your assistant can now delete saved agents itself. Ask it something like "remove the old layou-dev everywhere": it finds every agent with that exact name across the projects open in AgentsRoom (layou-dev never matches layou-dev-v2), and shows you one confirmation card listing them all. One click deletes the whole list, and the same card appears on your phone too. If you decline or don't answer, nothing is deleted.
In the app, you can do it without an agent: the eraser button above the agent list > "Delete agents in all projects". It lists every saved agent of your open projects, grouped by name. Tick a name to remove it from every project, or use "Select duplicates" to keep only the most recently used copy in each project. Right-click an agent > "Delete in all projects" opens the same window with that agent already ticked.
If it's not quite what you had in mind, tell us and we'll adjust it.