Fix release CI: stale bread-theme tag path + calamares default-branch clone

- release-iso.yml's "Build bread-theme from source" step grepped
  bos-settings/Cargo.toml for the bread-theme tag pin, but bos-settings was
  split out into its own repo (git.breadway.dev/Breadway/bos-settings) --
  that path no longer exists in this checkout, so the grep would fail (or
  silently find nothing). Now fetches bos-settings' Cargo.toml directly from
  its own repo (dev branch, the one its own CI actually publishes the
  bos-settings pacman package from) via the Forgejo raw-file endpoint.

- calamares.yml cloned the repo's default branch instead of the branch/tag
  that actually triggered the run -- bibata.yml, powerlevel10k.yml, and
  yay-bin.yml (the other in-house-PKGBUILD workflows in this same family)
  all correctly clone --branch "${GITHUB_REF_NAME}". Brought calamares.yml
  in line with them.

- breadhelp-tour.lua interpolated an untrusted, client-controlled Wayland
  window class / layer-shell namespace directly into a bread.exec shell
  command string -- a session-level shell injection vector (verified
  exploitable with a crafted window class before this fix, e.g.
  "evil; touch ~/pwned #"). bread.exec only accepts a single shell string
  (always run via `sh -lc`, per breadd/src/lua/mod.rs) -- there's no
  array-exec form to bypass the shell with -- so the fix is a proper POSIX
  shell_quote() helper wrapping every interpolated value in single quotes
  before it reaches bread.exec.

.forgejo/workflows/calamares.yml

@@ -24,7 +24,12 @@ jobs:
             kcoreaddons kpmcore libpwquality qt6-declarative qt6-svg yaml-cpp
           useradd -m builder
           git config --global --add safe.directory '*'
-          git clone --depth 1 "https://git.breadway.dev/${GITHUB_REPOSITORY}.git" /home/builder/src
+          # Clone the branch/tag that triggered this run (not the default
+          # branch) — same as bibata.yml/powerlevel10k.yml/yay-bin.yml, so a
+          # push to a feature branch (or a release tag) builds and publishes
+          # from that ref, not whatever happens to be on the default branch.
+          git clone --depth 1 --branch "${GITHUB_REF_NAME}" \
+            "https://git.breadway.dev/${GITHUB_REPOSITORY}.git" /home/builder/src
           chown -R builder:builder /home/builder/src
           su builder -c "cd /home/builder/src/packaging/calamares && makepkg -f --noconfirm --nocheck"
           PKG=$(find /home/builder/src/packaging/calamares -name '*.pkg.tar.zst' | head -1)