### What happened

When displays are reconfigured, connected, or disconnected (e.g., unplugging an external monitor, docking/undocking, or disabling an internal eDP panel when an external DP display is activated), `quickshell` crashes with `SIGSEGV` in `libjemalloc.so.2` via `libgdk-3.so.0`.

`omarchy-launch-shell` immediately relaunches `quickshell`, but running shell sessions and open panels flicker or drop during the crash/restart cycle.

### What was expected

`quickshell` should handle display additions and removals cleanly without crashing.

### Steps to reproduce

1. Start an Omarchy session.
2. Connect or disconnect an external display (e.g., hotplug a DisplayPort monitor, or close the laptop lid while docked causing `monitorremoved>>eDP-1`).
3. Inspect `coredumpctl list quickshell` or journal logs (`omarchy-shell` / `systemd-coredump`). Quickshell dumps core with `SIGSEGV`.

### Root Cause Analysis

1. In `/usr/share/omarchy/default/hypr/envs.lua`, Omarchy exports `QT_QPA_PLATFORMTHEME="gtk3"`.
2. `/usr/share/omarchy/bin/omarchy-launch-shell` runs `quickshell` with inherited environment variables. As a Qt 6 application, `quickshell` loads the `qgtk3` platform theme plugin (`libqgtk3.so`), which initializes GDK 3's Wayland backend (`libgdk-3.so.0`). This opens a secondary Wayland connection inside the Quickshell process alongside Qt's own connection.
3. In `libgdk-3.so.0` (gtk3 3.24.52), `gdk_wayland_monitor_finalize` destroys the `wl_output` object but fails to destroy `zxdg_output_v1`.
4. When Hyprland emits display removal events (e.g., `monitorremoved>>eDP-1`), GDK immediately finalizes the `GdkWaylandMonitor` struct.
5. In the same event dispatch iteration, GDK's event queue processes the pending `zxdg_output_v1` event (opcode 3: `name`) and invokes `xdg_output_handle_name` with the listener's `user_data` pointing to the now-freed `GdkWaylandMonitor` (use-after-free).
6. That memory block in `jemalloc` has already been reallocated to another object (in our dump, a `QString`). At offset `+0x98` (where `monitor->name` was expected), `xdg_output_handle_name` reads overwritten memory (`0x0074006e00650072` / `"rent"` in UTF-16) and passes it to `g_free()`, triggering an immediate segfault inside `libjemalloc.so.2`.

#### Stack Trace
```text
#0  0x0000703a2243e6f0 in <signal handler called> () at /usr/lib/libc.so.6
#1  0x0000703a25f09226 in libjemalloc.so.2
#2  0x0000703a25e54450 in libjemalloc.so.2
#3  0x0000703a1d77667e in xdg_output_handle_name () at /usr/lib/libgdk-3.so.0
#4  0x0000703a24dccdb6 in ffi_call_unix64 () at /usr/lib/libffi.so.8
#5  0x0000703a24dcbe32 in ffi_call () at /usr/lib/libffi.so.8
#6  0x0000703a25d927cd in wl_closure_invoke () at /usr/lib/libwayland-client.so.0
#7  0x0000703a25d93aeb in wl_display_dispatch_queue_pending () at /usr/lib/libwayland-client.so.0
#8  0x0000703a1d73629b in gdk_display_get_event () at /usr/lib/libgdk-3.so.0
#9  0x0000703a257f5055 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#10 0x0000703a23096f32 in QEventDispatcherGlib::processEvents () at /usr/lib/libQt6Core.so.6
#11 0x0000703a22d8685a in QCoreApplication::exec () at /usr/lib/libQt6Core.so.6
#12 0x000056b1db1e2085 in quickshell ()
```

### Suggested Fix

Quickshell is a pure QML/QtQuick shell using layer-shell and does not render GTK widgets. It does not need `QT_QPA_PLATFORMTHEME=gtk3`.

Unset `QT_QPA_PLATFORMTHEME` for `quickshell` in `/usr/share/omarchy/bin/omarchy-launch-shell`:

```bash
run_shell() {
  QT_QPA_PLATFORMTHEME="" \
  QS_DISABLE_FILE_WATCHER=1 QS_NO_RELOAD_POPUP=1 \
    systemd-cat -t omarchy-shell -- quickshell -n -p "$OMARCHY_PATH/shell" &
```

This prevents `libqgtk3.so` from loading, avoids initializing an unneeded secondary GDK Wayland client inside the shell, and protects `quickshell` from GTK 3's output teardown use-after-free bug.

### System details

- **Omarchy version:** `4.0.4-1`
- **OS:** Omarchy 4.0.4 (Arch Linux base, kernel `7.2.5-3-omarchy x86_64`)
- **Desktop:** Hyprland `0.56.2`
- **Quickshell:** `0.3.1-1`
- **GTK3:** `1:3.24.52-1`
- **Device:** Lenovo ThinkPad X1 Carbon Gen 11 (Intel Iris Xe Graphics)

> Filed by Gemini 3.8 Flash via Antigravity.