logiguard fork: GPUI xdg-activation keyboard-focus serial fix

Single-commit orphan branch: full zed-industries/zed @ 8c74db0 source tree
with a 3-file patch applied (no upstream history).

Patch (crates/gpui_linux/src/linux/wayland/):
  - 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)

Mutter honors window activation only when the token carries the keyboard-
focus serial from wl_keyboard.enter; GPUI used a stale mouse-press serial.
See docs/tray-window-focus-wayland.md in logiguard.

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

docs/src/extensions/themes.md

@@ -0,0 +1,63 @@
+---
+title: Themes
+description: "Themes for Zed extensions."
+---
+
+# Themes
+
+The `themes` directory in an extension should contain one or more theme files.
+
+Each theme file should adhere to the JSON schema specified at [`https://zed.dev/schema/themes/v0.2.0.json`](https://zed.dev/schema/themes/v0.2.0.json).
+
+See [this blog post](https://zed.dev/blog/user-themes-now-in-preview) for additional background on creating themes.
+
+## Theme JSON Structure
+
+The structure of a Zed theme is defined in the [Zed Theme JSON Schema](https://zed.dev/schema/themes/v0.2.0.json).
+
+A Zed theme consists of a Theme Family object including:
+
+- `name`: The name for the theme family
+- `author`: The name of the author of the theme family
+- `themes`: An array of Themes belonging to the theme family
+
+The core components of a Theme object include:
+
+1. Theme Metadata:
+
+   - `name`: The name of the theme
+   - `appearance`: Either "light" or "dark"
+
+2. Style Properties under the `style`, such as:
+
+   - `background`: The main background color
+   - `foreground`: The main text color
+   - `accent`: The accent color used for highlighting and emphasis
+
+3. Syntax Highlighting:
+
+   - `syntax`: An object containing color definitions for various syntax elements (e.g., keywords, strings, comments)
+
+4. UI Elements:
+
+   - Colors for various UI components such as:
+     - `element.background`: Background color for UI elements
+     - `border`: Border colors for different states (normal, focused, selected)
+     - `text`: Text colors for different states (normal, muted, accent)
+
+5. Editor-specific Colors:
+
+   - Colors for editor-related elements such as:
+     - `editor.background`: Editor background color
+     - `editor.gutter`: Gutter colors
+     - `editor.line_number`: Line number colors
+
+6. Terminal Colors:
+   - ANSI color definitions for the integrated terminal
+
+## Designing Your Theme
+
+You can use [Zed's Theme Builder](https://zed.dev/theme-builder) to design your own custom theme based on an existing one.
+
+This tool lets you fine-tune and preview how surfaces in Zed will look.
+You can then export the JSON and publish it in Zed's extension store.