Archive an app from its page or the apps list: spun down, hidden, restorable in one tap #10870

Replaces #10779, whose two pulls went red only on main's own red (the pill script size, planned first). Start from the branch mason/10779-archive-an-app-from-its-page-or-the-apps at 10f2867f8ca4, rebased on main; reuse repository archive (src/actions/repos.ts setArchived, the archive MCP tool), do not duplicate it.

Done when:

• [ ] An admin archives an app in one tap with a confirm; its process stops, it leaves home and the default apps list, its data and git stay, and its URL still answers.
• [ ] An 'Archived' filter on the apps list shows them with Restore; restore starts it again.
• [ ] The same action is reachable through the existing archive MCP tool; bun test test/mcp-size.test.ts passes without raising ceilings.
• [ ] Tests for archive, hidden, reachable by URL, restore.

duplicate of #10779