Merge branch 'main' of https://gitea.federated.computer/Federated_Computer/coredesktop

Brings in the shellcheck lint and bats tests. Both sides fixed the same
shellcheck warnings; this keeps the remote's versions of 20-aur.sh,
80-gnome-extensions.sh and .shellcheckrc, which silence false positives
per line rather than for the whole repo.

The Gitea workflow now runs make lint, so it checks the same scripts as
the Makefile, and the README points contributors at make check. The test
helper's REPO, used only by the .bats files, is marked for shellcheck,
and the update test expects the pull to be fast-forward only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

updates.d/20-aur.sh

@@ -12,9 +12,11 @@ if ! yay --version &>/dev/null; then
     sudo pacman -R --noconfirm yay
     cd /tmp || exit 1
     rm -rf yay
-    git clone https://aur.archlinux.org/yay.git && cd yay || exit 1
+    git clone https://aur.archlinux.org/yay.git
+    cd yay || exit 1
     makepkg -si --noconfirm
-    cd .. && rm -rf yay
+    cd ..
+    rm -rf yay
     cd || exit 1
 fi
 

updates.d/80-gnome-extensions.sh

@@ -50,7 +50,7 @@ reinstall_incompatible_extensions() {
       rm -rf "$backup"
     else
       echo "Reinstall of $uuid failed; restoring the previous version."
-      rm -rf "${ext_root:?}/$uuid"
+      rm -rf "${ext_root:?}/${uuid:?}"
       mv "$backup/$uuid" "$ext_root/$uuid"
       rmdir "$backup"
     fi