fix: Single-file build for curl, published by GitHub Actions

tools/bundle.sh inlines lib/ into one script; the workflow builds and
checks it on every push and PR, and on main publishes it to the rolling
"latest" release. Piped in via curl, it reattaches the terminal so the
menu keeps working.

.github/workflows/bundle.yml

@@ -0,0 +1,54 @@
+# Builds the single-file wizard (tools/bundle.sh) and publishes it as the
+# asset of the rolling "latest" release, for:
+#   bash <(curl -fsSL https://github.com/theupriser/cachyos-gamescope-boot/releases/download/latest/setup-gamescope-boot.sh)
+# Pull requests only build and check it.
+name: Single-file build
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: write
+
+jobs:
+  bundle:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # for the version in the bundle's header
+
+      - name: Build
+        run: tools/bundle.sh dist/setup-gamescope-boot.sh
+
+      - name: Check
+        run: |
+          bash -n dist/setup-gamescope-boot.sh
+          # SC2034/SC2154: variables used across the inlined modules.
+          shellcheck -S warning -e SC2034,SC2154 dist/setup-gamescope-boot.sh
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: setup-gamescope-boot
+          path: dist/setup-gamescope-boot.sh
+
+      - name: Publish to the "latest" release
+        if: github.event_name != 'pull_request' && github.ref == 'refs/heads/main'
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          notes="Single-file build of $(git describe --always) ($(git log -1 --format=%cs)).
+          Run it with:
+
+              bash <(curl -fsSL https://github.com/${{ github.repository }}/releases/download/latest/setup-gamescope-boot.sh)"
+          if gh release view latest >/dev/null 2>&1; then
+            gh release edit latest --notes "$notes"
+          else
+            gh release create latest --title "Latest single-file build" --notes "$notes" --latest
+          fi
+          # Move the tag to this commit and replace the asset.
+          git tag -f latest && git push -f origin latest
+          gh release upload latest dist/setup-gamescope-boot.sh --clobber