interactive: Host/View entry menu, clipboard copy, player picker

Bare `pixelpass` now opens a dialoguer-driven Host/View menu instead of
going straight to host mode. Host path copies the ticket to the system
clipboard via arboard with silent print-only fallback. View path
prompts for the ticket, then after the local listener binds prompts
mpv-vs-VLC and spawns it detached (setsid + null stdio) so the player
survives pixelpass exiting.

Headless invocations (`pixelpass <ticket>`, `pixelpass --repair`)
unchanged. Per spec at ~/Documents/pixelpass-interactive-mode-spec.md.

Cargo.toml

@@ -28,6 +28,8 @@ pipewire = "0.9"
 x11rb = { version = "0.13", default-features = false, features = ["allow-unsafe-code"] }
 uuid = { version = "1", features = ["v4"] }
 iroh-tickets = "1.0.0-rc.0"
+dialoguer = { version = "0.12", default-features = false }
+arboard = { version = "3", default-features = false, features = ["wayland-data-control"] }
 
 [profile.release]
 lto = "thin"