diff --git a/.github/workflows/check-codes-comment.yml b/.github/workflows/check-codes-comment.yml
deleted file mode 100644
index b323e1b45f..0000000000
--- a/.github/workflows/check-codes-comment.yml
+++ /dev/null
@@ -1,21 +0,0 @@
-name: Check Codes Comment
-
-# Disabled on this Gitea fork: the upstream flow depends on reviewdog
-# (missing from git.nest.potatolab.uk) and a checkstyle-artifact produced by
-# check-codes.yml. Re-enable only after those actions are mirrored or the
-# comment path is rewritten without reviewdog.
-on:
-  workflow_dispatch:
-
-permissions:
-  actions: read
-  contents: read
-  pull-requests: write
-
-jobs:
-  comment:
-    runs-on: ubuntu-latest
-    if: false
-    steps:
-      - name: Disabled
-        run: echo "check-codes-comment is disabled on this fork"
diff --git a/.github/workflows/check-codes.yml b/.github/workflows/check-codes.yml
deleted file mode 100644
index 52971f9345..0000000000
--- a/.github/workflows/check-codes.yml
+++ /dev/null
@@ -1,35 +0,0 @@
-name: Check Codes
-
-on:
-  workflow_dispatch:
-  push:
-    paths:
-      - '**.java'
-      - '**.properties'
-      - '.github/workflows/check-codes.yml'
-  pull_request:
-    paths:
-      - '**.java'
-      - '**.properties'
-      - '.github/workflows/check-codes.yml'
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v6
-      - name: Setup JDK 17
-        uses: actions/setup-java@v5
-        with:
-          distribution: 'zulu'
-          java-version: '17'
-          java-package: 'jdk+fx'
-      - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v5
-        with:
-          cache-cleanup: never
-      # Keep only Gradle checks. reviewdog/action-setup is not mirrored on
-      # git.nest.potatolab.uk (404), so PR-comment artifact steps are omitted
-      # for Gitea Actions / act runners.
-      - name: Check Codes
-        run: ./gradlew checkstyle checkTranslations --no-daemon --parallel --stacktrace
diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index 5a7bacbb54..76c24e7d5c 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -1,11 +1,22 @@
 name: Java CI
 
+# Pushes to main and pull requests only. A branch with an open pull request used to build twice
+# (once for the push, once for the pull request), which kept the runners queued.
 on:
   push:
+    branches:
+      - main
+    tags:
+      - '*'
   pull_request:
     paths-ignore:
       - '**.md'
 
+# A newer run for the same pull request or branch replaces the older one.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
 
@@ -23,12 +34,26 @@ jobs:
       uses: gradle/actions/setup-gradle@v5
       with:
         cache-cleanup: never
+        # Only main writes the dependency cache; pull requests read it.
+        cache-read-only: ${{ github.ref != 'refs/heads/main' }}
+    # The repository's wrapper downloads Gradle itself, so cache that download too.
+    - name: Cache Gradle distribution
+      uses: actions/cache@v4
+      with:
+        path: |
+          ~/.gradle/wrapper
+          .gradle/wrapper-neo
+        key: gradle-dist-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties', 'gradle/wrapper/GradleWrapperNeo.java') }}
     - name: Install Xvfb
       run: |
-        sudo apt-get update
-        sudo apt-get install -y xvfb
-    - name: Build with Gradle
-      run: xvfb-run --auto-servernum ./gradlew build --no-daemon --parallel
+        # Installing is the slowest setup step, so skip it when the runner already has xvfb, and
+        # only refresh the package index when a plain install fails.
+        command -v xvfb-run >/dev/null || sudo apt-get install -y --no-install-recommends xvfb \
+          || { sudo apt-get update && sudo apt-get install -y --no-install-recommends xvfb; }
+    # One Gradle run builds, tests and runs the code and translation checks, so the
+    # project is configured and compiled once instead of in two workflows.
+    - name: Build and check with Gradle
+      run: xvfb-run --auto-servernum ./gradlew build checkstyle checkTranslations --no-daemon --parallel
       env:
         JAVA_TOOL_OPTIONS: -Djava.awt.headless=true
         MICROSOFT_AUTH_ID: ${{ secrets.MICROSOFT_AUTH_ID }}