GNOME Shell crashes with SIGABRT when launching Zed editor (Mutter paint assertion failure, GNOME 50)

**Describe the bug**

GNOME Shell crashes entirely (SIGABRT / signal 6) when launching the Zed editor. The crash is a Mutter/Clutter assertion failure in the paint pipeline — `clutter_actor_continue_paint` → `clutter_paint_node_paint` → `meta_window_actor_paint_to_content`. Disabling Tiling Shell resolves the issue completely.

**To Reproduce**
1. Install Tiling Shell v17.3 on GNOME 50 / Mutter 50 (Wayland)
2. Install Zed editor (v1.9.0) — a GPU-accelerated, Vulkan-based code editor
3. Launch Zed from the app menu or terminal (`zeditor`)
4. GNOME Shell crashes immediately, user is logged out

**Expected behavior**
Zed opens normally without crashing the shell.

**Stack trace (from coredump)**
```
#0 pthread_kill (libc.so.6)
#1 raise (libc.so.6)
#2 abort (libc.so.6)
#3 g_assertion_message_expr (libglib-2.0.so.0)
#4 clutter_actor_continue_paint (libmutter-clutter-18.so.0)
#5 clutter_paint_node_paint (libmutter-clutter-18.so.0)
#6 clutter_actor_paint (libmutter-clutter-18.so.0)
#7 meta_window_actor_paint_to_content (libmutter-18.so.0)
```

Also present in journal before crash:
```
Attempting to call back into JSAPI during the sweeping phase of GC. This is most likely caused by not destroying a Clutter actor or Gtk+ widget with ::destroy signals connected...
```

**Environment**
- Tiling Shell version: **17.3**
- GNOME version: **50.3** (Mutter 50.3-1.1)
- Desktop: GNOME on **Wayland**
- GPU: Intel Alder Lake (Mesa Intel Graphics, Mesa 26.1.4)
- Distro: CachyOS (Arch Linux, rolling)
- Zed version: 1.9.0

**Additional context**
- Issue #579 reports a similar GNOME 50 rendering problem (windows failing to render), but this is more severe — it kills the entire GNOME Shell session.
- v17.3 does not list GNOME 50 in its metadata.json shell-version (same as #579). v18.0 RC (#582) adds GNOME 50 support — this crash may already be fixed there.
- Zed uses Vulkan for GPU-accelerated rendering, which likely triggers a different paint path than regular GTK apps.
- Workaround: disabling Tiling Shell, or launching Zed with `GDK_BACKEND=x11`.
- The `libmutter-clutter-18.so.0` shows as `(deleted)` in coredump metadata (library was replaced during a system update while the process was running).

Start by comparing v17.3's metadata.json with the GNOME 50 support added in the v18.0 RC referenced by #582, then reproduce the crash by launching Zed through Wayland with Tiling Shell enabled. Check whether the `clutter_actor_continue_paint` assertion and GC warning still occur; done means Zed launches without logging out the GNOME session.

Written by the indexing model from the issue text.