ci: make beta a branch-triggered freeze track, not a one-off tag

Beta is now a real stabilization branch: publishes on every push to
`beta` (mirroring dev's model, auto-versioned X.Y.Z-beta.<ts>+<sha>,
base version from the latest published tag) instead of a manual
beta-v* tag. Fixes made during the freeze land via fix/<issue> branches
merged into `beta` directly. The gen-index.sh clone for beta pulls
bread-ecosystem's default branch (main) rather than pinning to dev,
since beta is the more stable track and main now carries the
TRACK-aware script.

.forgejo/workflows/beta-release.yml

@@ -1,12 +1,12 @@
 name: beta release
 
-# Publishes a beta-track build when a `beta-v*` tag is pushed —
-# separate from release.yml's tag-triggered stable releases. See
-# bread-ecosystem's docs/release-channels.md for the three-track policy
-# this is part of.
+# Publishes a beta-track build on every push to `beta` — a frozen
+# stabilization branch cut from `dev` when ready to stabilize; only
+# fix/<issue> branches merged into `beta` should land here afterward.
+# See bread-ecosystem's docs/release-channels.md for the three-track policy.
 on:
   push:
-    tags: ['beta-v*']
+    branches: ['beta']
 
 jobs:
   build:
@@ -16,7 +16,7 @@ jobs:
         run: |
           set -euo pipefail
           rm -rf src && mkdir src
-          git clone --branch "${GITHUB_REF_NAME}" --depth 1 \
+          git clone --branch beta --depth 1 \
             "https://git.breadway.dev/${GITHUB_REPOSITORY}.git" src
 
       - name: build
@@ -25,10 +25,31 @@ jobs:
       - name: test
         run: cd src && cargo test --release --locked
 
+      - name: compute beta version
+        run: |
+          set -euo pipefail
+          cd src
+          # Base the beta version off the latest published stable tag,
+          # not Cargo.toml — Cargo.toml can go stale relative to the last
+          # real release (seen in practice: breadbox/breadpad/breadcrumbs/
+          # breadpaper), which would make a beta build sort as OLDER than
+          # what's already installed and bakery would correctly refuse it.
+          LATEST_TAG="$(git ls-remote --tags --refs \
+            "https://git.breadway.dev/${GITHUB_REPOSITORY}.git" 'v*' \
+            | awk -F/ '{print $NF}' | sed 's/^v//' | sort -V | tail -1)"
+          if [ -n "${LATEST_TAG}" ]; then
+            CUR="${LATEST_TAG}"
+          else
+            CUR="$(grep -m1 '^version' Cargo.toml | sed -E 's/.*"(.*)".*/\1/')"
+          fi
+          IFS='.' read -r MA MI PA <<< "${CUR}"
+          SHA="$(git rev-parse --short HEAD)"
+          TS="$(date -u +%Y%m%d%H%M%S)"
+          echo "VERSION=${MA}.${MI}.$((PA + 1))-beta.${TS}+${SHA}" >> "$GITHUB_ENV"
+
       - name: prepare artifacts
         run: |
           set -euo pipefail
-          VERSION="${GITHUB_REF_NAME#beta-v}"
           PKG_DIR="/srv/breadway-dl/beta/breadpaper/${VERSION}"
           mkdir -p "${PKG_DIR}"
           cp "src/target/release/breadpaper" "${PKG_DIR}/breadpaper-x86_64"
@@ -38,8 +59,8 @@ jobs:
           cp src/bakery.toml "${PKG_DIR}/bakery.toml"
           ln -sfn "${VERSION}" "/srv/breadway-dl/beta/breadpaper/latest"
 
-      # No GitHub Release upload — beta, like the other non-stable track,
-      # is only distributed via dl.breadway.dev/beta/.
+      # No GitHub Release upload — beta, like dev, is only distributed via
+      # dl.breadway.dev/beta/.
       - name: regenerate beta index.json
         env:
           MINISIGN_SEC_KEY: ${{ secrets.BAKERY_MINISIGN_SEC_KEY_PATH }}
@@ -53,6 +74,6 @@ jobs:
           # mktemp: a fixed clone path races when multiple repos' dev/beta
           # workflows run close together on the same self-hosted runner.
           ECOSYSTEM_CI_DIR="$(mktemp -d /tmp/bread-ecosystem-ci-XXXXXX)"
-          git clone --branch dev https://git.breadway.dev/Breadway/bread-ecosystem.git "${ECOSYSTEM_CI_DIR}"
+          git clone https://git.breadway.dev/Breadway/bread-ecosystem.git "${ECOSYSTEM_CI_DIR}"
           TRACK=beta bash "${ECOSYSTEM_CI_DIR}/scripts/gen-index.sh"
           rm -rf "${ECOSYSTEM_CI_DIR}"