added github mirror

.gitea/workflows/github_mirror.yaml

@@ -0,0 +1,56 @@
+name: Mirror main to GitHub (shallow)
+
+on:
+  push:
+    branches: ["main"]        # nur main triggern
+  workflow_dispatch:          # manuell startbar
+
+concurrency:
+  group: mirror-main-to-github
+  cancel-in-progress: false
+
+jobs:
+  mirror:
+    runs-on: ubuntu-latest
+    steps:
+
+      - name: Checkout (shallow, no history)
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1       # <— wichtig: keine alte Historie
+          lfs: true            # falls LFS-Dateien im aktuellen Commit liegen
+
+      - name: Install git-lfs
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y git-lfs
+          git lfs install
+
+      - name: Add GitHub remote
+        env:
+          GH_USER: ${{ secrets.GH_USER }}
+          GH_TOKEN: ${{ secrets.GH_TOKEN }}
+          GH_OWNER: ${{ secrets.GH_OWNER }}
+          GH_REPO: ${{ secrets.GH_REPO }}
+        run: |
+          set -euo pipefail
+          : "${GH_USER?missing}"; : "${GH_TOKEN?missing}"; : "${GH_OWNER?missing}"; : "${GH_REPO?missing}"
+          git remote remove mirror 2>/dev/null || true
+          git remote add mirror "https://${GH_USER}:${GH_TOKEN}@github.com/${GH_OWNER}/${GH_REPO}.git"
+
+      - name: Push main branch (shallow)
+        run: |
+          # force ist i. d. R. nicht nötig; nur, wenn du auf GitHub main überschreiben willst
+          git push mirror HEAD:refs/heads/main
+
+      - name: Push LFS objects for current commit
+        env:
+          GH_USER: ${{ secrets.GH_USER }}
+          GH_TOKEN: ${{ secrets.GH_TOKEN }}
+          GH_OWNER: ${{ secrets.GH_OWNER }}
+          GH_REPO: ${{ secrets.GH_REPO }}
+        run: |
+          set -euo pipefail
+          REMOTE="https://${GH_USER}:${GH_TOKEN}@github.com/${GH_OWNER}/${GH_REPO}.git"
+          # Nur Objekte, die lokal vorhanden sind (durch lfs: true) – somit kein Altbestand
+          git lfs push "$REMOTE" --all