CI: keep the Maven cache warm so builds stop re-downloading Central

.github/workflows/build.yml

@@ -5,6 +5,8 @@ on:
     branches: [ "main" ]
   pull_request:
     branches: [ "main" ]
+  # Manual runs: on main this publishes orbitalhq/nebula:next, same as a push build
+  workflow_dispatch:
 
 jobs:
   build-jvm:
@@ -18,14 +20,8 @@ jobs:
           java-version: '21'
           distribution: 'temurin'
           cache: maven
-      - name: Cache Maven packages
-        uses: actions/cache@v4
-        with:
-          path: ~/.m2
-          key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
-          restore-keys: ${{ runner.os }}-m2
       - name: Deploy with Maven
-        run: mvn clean deploy --settings .mvn/settings.xml
+        run: mvn clean deploy -B -ntp -Dmaven.artifact.threads=16 --settings .mvn/settings.xml
         env:
           AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
           AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}

.github/workflows/warm-maven-cache.yml

@@ -0,0 +1,32 @@
+name: Warm Maven cache
+
+# GitHub evicts any Actions cache that hasn't been accessed for 7 days.
+# This repo often goes quiet for weeks at a time, so builds routinely start
+# with a cold cache and re-download every artifact from Maven Central.
+# This job touches the cache twice a week (and rebuilds it when poms change),
+# keeping it inside the eviction window so real builds restore it instead.
+#
+# Note: GitHub auto-disables scheduled workflows after 60 days without repo
+# activity - re-enable it from the Actions tab if the repo has been dormant.
+
+on:
+  schedule:
+    - cron: '17 5 * * 1,4' # Mon + Thu, comfortably inside the 7-day window
+  workflow_dispatch:
+
+jobs:
+  warm-cache:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+          cache: maven
+      - name: Resolve dependencies
+        run: mvn -B -ntp -Dmaven.artifact.threads=16 dependency:go-offline --settings .mvn/settings.xml
+        env:
+          JOOQ_REPO_USERNAME: ${{ secrets.JOOQ_REPO_USERNAME }}
+          JOOQ_REPO_PASSWORD: ${{ secrets.JOOQ_REPO_PASSWORD }}