feat(app): show draft server status in titlebar

[Brendonovich]

Summary

• show the server status action in the /new-session title bar when status visibility is enabled
• keep status data scoped to the draft's selected server and directory
• share titlebar right-mount discovery between session and draft routes

Validation

• bun typecheck from packages/app
• bun run test:unit from packages/app (543 tests)
• repository pre-push typecheck (30 packages)