CI: port breadcrumbs onto bread-ecosystem's shared Arch build image

Adds ci/build.sh + ci/bread-ecosystem.rev (pinned to bread-ecosystem
147cfbb) following the pattern proven in breadpad, so releases build
inside the shared pinned container instead of installing toolchain
deps directly on the bare runner. Routes dev/rc/release build+test
steps through it and adds a check.yml for fast clippy/test feedback
on feature/fix branches. No ci/deps.txt — breadcrumbs' dependencies
(clap/serde/toml/serde_json) are pure Rust with no system library
needs; nmcli/tailscale/sudo/xdg-open are shelled out to, not linked.

.forgejo/workflows/dev-release.yml

@@ -19,7 +19,7 @@ jobs:
             "https://git.breadway.dev/${GITHUB_REPOSITORY}.git" src
 
       - name: build
-        run: cd src && cargo build --release --locked
+        run: cd src && bash ci/build.sh cargo build --release --locked
 
       - name: compute dev version
         run: |