README: stop promising five faces at 1.0 #12

The headline is "One backend, five faces" and 1.0 ships two. The phase plan already calls Phases 4 and 5 out of scope while the diagram still promises them.

Done when:

• The faces diagram distinguishes what exists from what is planned.
• The phase plan gains a v1.0 entry: a daemon that self-heals and reports its own health, plus two TUI faces.
• Menu-bar pet, sonifier and wallpaper are explicitly post-1.0.
• The Paths table collapses to one entry once signal-client owns resolution; workspace layout gains signal-client/, terminal-pet/, supervisor.rs.