fix(build): ensure gtk4-layer-shell loads before libwayland-client

- Update CGO_LDFLAGS in build scripts to include gtk4-layer-shell with the correct load order.
- Add a new layershell_link.go file to maintain the dependency on gtk4-layer-shell.
- Modify overlay_gtk.go to clarify the importance of load order for Layer Shell functionality.
- Enhance run.sh to preload gtk4-layer-shell for proper overlay positioning.

scripts/ci/package-release.sh

@@ -32,11 +32,12 @@ mkdir -p -- \
 
 # The Sherpa Go module embeds an absolute build-machine RPATH. Add a portable
 # build-time fallback; the final paths are normalized after dependency copying.
+# gtk4-layer-shell must precede libwayland-client so its Wayland shim installs.
 # shellcheck disable=SC2016 # $ORIGIN must remain literal for the ELF loader.
-CGO_LDFLAGS='-Wl,-rpath,$ORIGIN/lib' \
+CGO_LDFLAGS='-Wl,--no-as-needed -lgtk4-layer-shell -Wl,-rpath,$ORIGIN/lib' \
   go build -trimpath -o "$package_dir/captioneer" ./src/cmd/captioneer
 # shellcheck disable=SC2016 # $ORIGIN must remain literal for the ELF loader.
-CGO_LDFLAGS='-Wl,-rpath,$ORIGIN/lib' \
+CGO_LDFLAGS='-Wl,--no-as-needed -lgtk4-layer-shell -Wl,-rpath,$ORIGIN/lib' \
   go build -trimpath -tags gtk \
     -o "$package_dir/captioneer-desktop" ./src/cmd/captioneer-desktop