Machines UI follow-ups seen during Task 7548

Seen on the live stack while checking Task 7548 (desktop 1440px and phone 420px): 1. Add node wizard: "Operator Cloud" and "Self-Hosted" cards have no one-line description, while "Jaah Cloud" and "Virtual Node" do. Give every option card a one-line description. 2. Add node wizard: the "Virtual Node" card says "None of your hosts can take another node" but stays selectable. Disable it, showing that reason, when no host can take a node. 3. Node page Overview on a phone: the Accounts fact breaks out of the two-column facts grid onto its own full-width row, and the Created label and value sit out of line with their neighbours. Keep the facts in one aligned grid. 4. Host page header: a disabled "Add node" button with a sentence-long reason beside it ("Re-create this machine to add nodes.") crowds the title row. Move the reason into the button's tooltip or a short caption below it. Out of scope: server changes; the MicroVM tab. Done means: - Each item is shipped or declined with a reason. - Screenshots at desktop and ≤448px. Required checks: ./dc check full

Shipped all 4 Machines UI items (way descriptions, visibly-disabled Virtual Node, one-column phone facts, Add node reason as caption); visual check done at 1440/420, all read clean. PR #6088 merged via lane (1f910f1). Local full gate killed by memory pressure — CI/lane as gate. Draft follow-up #7577.