Pin ecosystem crates and switch to bread-utils::singleton

Repoint bread-theme and bread-utils at git.breadway.dev tag v0.7.1
(no github.com). bread-screenshots is not on that tag yet, so rev-pin
it instead of tracking branch=main.

Replace the homegrown PID-file toggle with bread-utils::singleton so
the launcher still dismisses on a second keybind without the TOCTOU
window. Screenshot mode still skips the lock.

README now documents the fixed BOS dark fallback (not Catppuccin
Mocha). Drop the unused GitHub Actions release workflow; Forgejo is
canonical. CONTRIBUTING already documents single-trunk.

.github/README.md

@@ -0,0 +1 @@
+Forgejo (`.forgejo/workflows`) is the canonical CI. This `.github` tree is unused.

.github/workflows/release.yml

@@ -1,67 +0,0 @@
-name: release
-
-on:
-  push:
-    tags: ["v*"]
-
-permissions:
-  contents: write
-
-env:
-  DL_DIR: /srv/breadway-dl
-  ECOSYSTEM_DIR: /home/breadway/Projects/bread-ecosystem
-
-jobs:
-  build:
-    runs-on: [self-hosted, hestia]
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: install build deps
-        run: sudo apt-get install -y libgtk-4-dev librsvg2-dev libdbus-1-dev pkg-config 2>/dev/null || true
-
-      - name: build
-        run: cargo build --release --locked
-
-      - name: prepare artifacts
-        run: |
-          VERSION="${GITHUB_REF_NAME#v}"
-          PKG_DIR="${DL_DIR}/breadbox/${VERSION}"
-          mkdir -p "${PKG_DIR}"
-          for bin in breadbox breadbox-sync; do
-            cp "target/release/${bin}" "${PKG_DIR}/${bin}-x86_64"
-            strip "${PKG_DIR}/${bin}-x86_64"
-            sha256sum "${PKG_DIR}/${bin}-x86_64" | awk '{print $1}' \
-              > "${PKG_DIR}/${bin}-x86_64.sha256"
-          done
-          cp packaging/breadbox-sync.service "${PKG_DIR}/"
-          cp config.example.toml "${PKG_DIR}/"
-          cp bakery.toml "${PKG_DIR}/bakery.toml"
-          ln -sfn "${VERSION}" "${DL_DIR}/breadbox/latest"
-
-      - name: ensure bread-ecosystem
-        run: |
-          if [[ -d "${ECOSYSTEM_DIR}/.git" ]]; then
-            git -C "${ECOSYSTEM_DIR}" pull --ff-only
-          else
-            mkdir -p "$(dirname "${ECOSYSTEM_DIR}")"
-            git clone https://github.com/Breadway/bread-ecosystem.git "${ECOSYSTEM_DIR}"
-          fi
-
-      - name: regenerate index.json
-        run: bash "${ECOSYSTEM_DIR}/scripts/gen-index.sh"
-
-      - name: upload to GitHub Release
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          VERSION="${GITHUB_REF_NAME#v}"
-          PKG_DIR="${DL_DIR}/breadbox/${VERSION}"
-          gh release create "${GITHUB_REF_NAME}" \
-            --title "breadbox v${VERSION}" --generate-notes 2>/dev/null || true
-          gh release upload "${GITHUB_REF_NAME}" \
-            "${PKG_DIR}/breadbox-x86_64" \
-            "${PKG_DIR}/breadbox-sync-x86_64" \
-            "${PKG_DIR}/breadbox-x86_64.sha256" \
-            "${PKG_DIR}/breadbox-sync-x86_64.sha256" \
-            --clobber