ci: port breadbar onto shared bread-ecosystem build system

Delegates dev/rc/release build steps to bread-ecosystem's pinned Arch
container via ci/build.sh, pinned to bread-ecosystem commit
147cfbbf96ae4b171027defa1130d2caddb934b1. Adds a check.yml workflow
for fast clippy/test signal on feature/fix branches, matching the
pattern proven in breadpad. No ci/deps.txt needed — breadbar's
dependencies (zbus, resvg, gtk4-layer-shell, hyprland) are all pure
Rust or already covered by the shared image's package set.

.forgejo/workflows/check.yml

@@ -0,0 +1,24 @@
+name: check
+
+# Fast-fail lint/test on short-lived work branches, before it ever reaches
+# main and triggers a dev-track release build.
+on:
+  push:
+    branches: ['feature/**', 'fix/**']
+
+jobs:
+  check:
+    runs-on: [self-hosted, hestia]
+    steps:
+      - name: checkout
+        run: |
+          set -euo pipefail
+          rm -rf src && mkdir src
+          git clone --branch "${GITHUB_REF_NAME}" --depth 1 \
+            "https://git.breadway.dev/${GITHUB_REPOSITORY}.git" src
+
+      - name: clippy
+        run: cd src && bash ci/build.sh cargo clippy --all-targets --locked -- -D warnings
+
+      - name: test
+        run: cd src && bash ci/build.sh cargo test --locked