gui of canvas is from the canvas crate now

canvas/Cargo.toml

@@ -11,7 +11,7 @@ categories.workspace = true
 
 [dependencies]
 common = { path = "../common" }
-ratatui = { workspace = true }
+ratatui = { workspace = true, optional = true }
 crossterm = { workspace = true }
 anyhow = { workspace = true }
 tokio = { workspace = true }
@@ -21,6 +21,10 @@ serde = { workspace = true }
 [dev-dependencies]
 tokio-test = "0.4.4"
 
+[features]
+default = []
+gui = ["ratatui"]
+
 [[example]]
 name = "simple_login"
 path = "examples/simple_login.rs"