feat(display): input routed via display server to focused app; input Subscribe; uses caps badged + Delegate

crates/types/src/display.rs

@@ -123,3 +123,13 @@ pub mod text {
         }
     }
 }
+
+/// Input through the display server: an app subscribes with a notification
+/// and is then the one keys go to (focus); when it is signalled it polls.
+/// A poll's reply is an input event exactly as the input server sends it
+/// (tag 0: no event).
+pub mod input {
+    /// Carries the notification to signal; the subscriber takes focus.
+    pub const SUBSCRIBE: usize = 5;
+    pub const POLL: usize = 6;
+}

crates/types/src/input.rs

@@ -0,0 +1,5 @@
+//! Input server requests other crates need to name.
+
+pub const POLL_EVENT: usize = 0;
+/// Carries a notification the server signals whenever new events arrive.
+pub const SUBSCRIBE: usize = 2;

crates/types/src/lib.rs

@@ -8,6 +8,7 @@ pub mod budget;
 pub mod display;
 pub mod generation;
 pub mod id;
+pub mod input;
 pub mod log;
 pub mod macros;
 pub mod mapping;