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>

.github/workflows/randomized_tests.yml

@@ -0,0 +1,36 @@
+name: Randomized Tests
+
+concurrency: randomized-tests
+
+on:
+  push:
+    branches:
+      - randomized-tests-runner
+  # schedule:
+  #    - cron: '0 * * * *'
+
+env:
+  CARGO_TERM_COLOR: always
+  CARGO_INCREMENTAL: 0
+  RUST_BACKTRACE: 1
+  ZED_SERVER_URL: https://zed.dev
+
+jobs:
+  tests:
+    name: Run randomized tests
+    if: github.repository_owner == 'zed-industries'
+    runs-on:
+      - namespace-profile-16x32-ubuntu-2204
+    steps:
+      - name: Install Node
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+        with:
+          node-version: "18"
+
+      - name: Checkout repo
+        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5.0.1
+        with:
+          clean: false
+
+      - name: Run randomized tests
+        run: script/randomized-test-ci