logiguard fork v2: patched GPUI on verified 8c74db0 tree

Rebuilt from the exact zed-industries/zed @ 8c74db00c4053d6c0a9037863d7bd048658da4ca
tree (previous orphan was based on a stale/wrong fetch). Same 3-file patch:
  - serial.rs: add SerialKind::KeyboardEnter
  - client.rs: store wl_keyboard.enter serial; add latest_serial_of()
  - window.rs: activate() uses keyboard-enter serial (Mutter focus gate)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

crates/gpui/docs/key_dispatch.md

@@ -0,0 +1,100 @@
+# Key Dispatch
+
+GPUI is designed for keyboard-first interactivity.
+
+To expose functionality to the mouse, you render a button with a click handler.
+
+To expose functionality to the keyboard, you bind an _action_ in a _key context_.
+
+Actions are similar to framework-level events like `MouseDown`, `KeyDown`, etc, but you can define them yourself:
+
+```rust
+mod menu {
+    #[gpui::action]
+    struct MoveUp;
+
+    #[gpui::action]
+    struct MoveDown;
+}
+```
+
+Actions are frequently unit structs, for which we have a macro. The above could also be written:
+
+```rust
+mod menu {
+    actions!(gpui, [MoveUp, MoveDown]);
+}
+```
+
+Actions can also be more complex types:
+
+```rust
+mod menu {
+    #[gpui::action]
+    struct Move {
+        direction: Direction,
+        select: bool,
+    }
+}
+```
+
+To bind actions, chain `on_action` on to your element:
+
+```rust
+impl Render for Menu {
+    fn render(&mut self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        div()
+            .on_action(|this: &mut Menu, move: &MoveUp, window: &mut Window, cx: &mut Context<Menu>| {
+                // ...
+            })
+            .on_action(|this, move: &MoveDown, cx| {
+                // ...
+            })
+            .children(unimplemented!())
+    }
+}
+```
+
+In order to bind keys to actions, you need to declare a _key context_ for part of the element tree by calling `key_context`.
+
+```rust
+impl Render for Menu {
+    fn render(&mut self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        div()
+            .key_context("menu")
+            .on_action(|this: &mut Menu, move: &MoveUp, window: &mut Window, cx: &mut Context<Menu>| {
+                // ...
+            })
+            .on_action(|this, move: &MoveDown, cx| {
+                // ...
+            })
+            .children(unimplemented!())
+    }
+}
+```
+
+Now you can target your context in the keymap. Note how actions are identified in the keymap by their fully-qualified type name.
+
+```json
+{
+  "context": "menu",
+  "bindings": {
+    "up": "menu::MoveUp",
+    "down": "menu::MoveDown"
+  }
+}
+```
+
+If you had opted for the more complex type definition, you'd provide the serialized representation of the action alongside the name:
+
+```json
+{
+  "context": "menu",
+  "bindings": {
+    "up": ["menu::Move", {direction: "up", select: false}]
+    "down": ["menu::Move", {direction: "down", select: false}]
+    "shift-up": ["menu::Move", {direction: "up", select: true}]
+    "shift-down": ["menu::Move", {direction: "down", select: true}]
+  }
+}
+```