Add named keyboard binding modes (#32)

Add named keyboard shortcut maps with an Escape exit and a panel indicator. Keep press/release ownership across transitions, validate remapped Escape keys, and cancel stale repeats and focus previews.

Give the indicator ownership of the panel while a mode is active. Close popovers, collapse Morph, and keep Live Activities data current without resizing the hidden panel. Document configuration and transition behavior.

Validation: 1,519 workspace Rust tests passed; 70 Python tests passed. Workspace build, formatting, Clippy, and Settings configuration validation passed. Opt-in native desktop checks were not rerun because Weston is absent.

Related: #5.

compositor/src/ipc.rs

@@ -1104,7 +1104,8 @@ impl Ferese {
             "get-keybindings" => {
                 let map = crate::config::physical_keymap(&self.input_settings).ok();
                 return Ok(json!(
-                    self.bindings
+                    self.binding_modes
+                        .bindings(&self.bindings)
                         .iter()
                         .filter_map(|binding| binding.guide_entry(map.as_ref()))
                         .take(256)