Update build-and-push workflow to align Helm chart image tag with build version

.gitea/workflows/build-and-push.yaml

@@ -91,13 +91,20 @@ jobs:
           tar -xzf helm.tgz
           sudo mv linux-amd64/helm /usr/local/bin/helm
           helm version
-      - name: Helm lint & template
+      # Chart publié avec le même tag que l’image (évite latest / oubli de --set au déploiement).
+      - name: Aligner slides.image.tag sur la version build
         env:
           VERSION: ${{ needs.vars.outputs.version }}
+        run: |
+          set -euo pipefail
+          f="${HELM_DIR}/values.yaml"
+          sed -i 's|^    tag: ".*"|    tag: "'"${VERSION}"'"|' "$f"
+          grep -E '^    tag:' "$f" || true
+      - name: Helm lint & template
         run: |
           set -euo pipefail
           helm lint "${HELM_DIR}"
-          helm template talks-slides "${HELM_DIR}" --set slides.image.tag="${VERSION}"
+          helm template talks-slides "${HELM_DIR}"
       - name: Package and push chart (OCI)
         if: github.event_name == 'push'
         env: