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/languages/c.md

@@ -0,0 +1,98 @@
+---
+title: C
+description: "Configure C language support in Zed, including language servers, formatting, and debugging."
+---
+
+# C
+
+C support is available natively in Zed.
+
+- Tree-sitter: [tree-sitter/tree-sitter-c](https://github.com/tree-sitter/tree-sitter-c)
+- Language Server: [clangd/clangd](https://github.com/clangd/clangd)
+- Debug Adapter: [CodeLLDB](https://github.com/vadimcn) (primary), [GDB](https://sourceware.org/gdb/) (secondary, not available on Apple silicon)
+
+## Clangd: Force detect as C
+
+Clangd out of the box assumes mixed C++/C projects. If you have a C-only project you may wish to instruct clangd to treat all files as C using the `-xc` flag. To do this, create a `.clangd` file in the root of your project with the following:
+
+```yaml
+# yaml-language-server: $schema=https://json.schemastore.org/clangd.json
+CompileFlags:
+  Add: [-xc]
+```
+
+By default clang and gcc will recognize `*.C` and `*.H` (uppercase extensions) as C++ and not C and so Zed too follows this convention. If you are working with a C-only project (perhaps one with legacy uppercase pathing like `FILENAME.C`) you can override this behavior by adding this to your settings:
+
+```json [settings]
+{
+  "file_types": {
+    "C": ["C", "H"]
+  }
+}
+```
+
+## Formatting
+
+By default Zed will use the `clangd` language server for formatting C code like the `clang-format` CLI tool. To configure this you can add a `.clang-format` file. For example:
+
+```yaml
+# yaml-language-server: $schema=https://json.schemastore.org/clang-format-21.x.json
+---
+BasedOnStyle: GNU
+IndentWidth: 2
+---
+```
+
+See [Clang-Format Style Options](https://clang.llvm.org/docs/ClangFormatStyleOptions.html) for a complete list of options.
+
+You can trigger formatting via {#kb editor::Format} or the {#action editor::Format} action from the command palette or by enabling format on save.
+
+Configure formatting in Settings ({#kb zed::OpenSettings}) under Languages > C, or add to your settings file:
+
+```json [settings]
+  "languages": {
+    "C": {
+      "format_on_save": "on",
+      "tab_size": 2
+    }
+  }
+```
+
+## Compile Commands
+
+For some projects Clangd requires a `compile_commands.json` file to properly analyze your project. This file contains the compilation database that tells clangd how your project should be built.
+
+### CMake Compile Commands
+
+With CMake, you can generate `compile_commands.json` automatically by adding the following line to your `CMakeLists.txt`:
+
+```cmake
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+```
+
+After building your project, CMake will generate the `compile_commands.json` file in the build directory and clangd will automatically pick it up.
+
+## Debugging
+
+You can use CodeLLDB or GDB to debug native binaries. (Make sure that your build process passes `-g` to the C compiler, so that debug information is included in the resulting binary.) See below for examples of debug configurations that you can add to `.zed/debug.json`.
+
+- [CodeLLDB configuration documentation](https://github.com/vadimcn/codelldb/blob/master/MANUAL.md#starting-a-new-debug-session)
+- [GDB configuration documentation](https://sourceware.org/gdb/current/onlinedocs/gdb.html/Debugger-Adapter-Protocol.html)
+
+### Build and Debug Binary
+
+```json [debug]
+[
+  {
+    "label": "Debug native binary",
+    "build": {
+      "command": "make",
+      "args": ["-j8"],
+      "cwd": "$ZED_WORKTREE_ROOT"
+    },
+    "program": "$ZED_WORKTREE_ROOT/build/prog",
+    "request": "launch",
+    "adapter": "CodeLLDB"
+  }
+]
+```