Make mod_version the source of truth for releases; bump to 0.1.1-beta

The release workflow no longer overrides mod_version from the tag.
Instead it fails early unless the release tag (optionally prefixed with
"v") matches mod_version in gradle.properties, so released jars always
report the same version as the code the version check sees.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

.gitea/workflows/release.yml

@@ -1,8 +1,9 @@
 name: Release
 
-# Publishing a release builds every Minecraft version from the release's tag
-# and attaches the mod jars to it. The tag is the mod version (e.g.
-# 0.1.1-beta); a leading "v" is dropped.
+# Publishing a release builds every Minecraft version and attaches the mod jars
+# to it. mod_version in gradle.properties is the source of truth: the release
+# tag must match it (a leading "v" is allowed), so bump mod_version in a PR
+# before tagging the release.
 on:
   release:
     types: [published]
@@ -19,6 +20,17 @@ jobs:
         with:
           submodules: true
 
+      - name: Check tag matches mod_version
+        env:
+          TAG: ${{ github.event.release.tag_name }}
+        run: |
+          MOD_VERSION="$(sed -n 's/^mod_version=//p' gradle.properties | tr -d '[:space:]')"
+          if [ "${TAG#v}" != "$MOD_VERSION" ]; then
+            echo "::error::Release tag '$TAG' doesn't match mod_version '$MOD_VERSION' in gradle.properties. Bump mod_version to '${TAG#v}' on the release branch, or tag the release '$MOD_VERSION'." >&2
+            exit 1
+          fi
+          echo "Building Saturn Client $MOD_VERSION"
+
       - name: Set up Java 21
         uses: actions/setup-java@v4
         with:
@@ -27,14 +39,10 @@ jobs:
           cache: gradle
 
       - name: Build all versions
-        env:
-          TAG: ${{ github.event.release.tag_name }}
         run: |
-          VERSION="${TAG#v}"
-          echo "Building Saturn Client $VERSION"
           chmod +x gradlew
           # buildAll remaps every versions/* project in parallel into build/allJars.
-          ./gradlew buildAll -Pmod_version="$VERSION" --no-daemon --stacktrace
+          ./gradlew buildAll --no-daemon --stacktrace
 
       - name: Upload jars to the release
         env: