fix: pass git commit hash as Docker build arg so footer shows correctly

git is not available inside the node:20-alpine Docker image, so
git rev-parse in next.config.ts falls back to 'dev'. Now the commit
hash is passed as a COMMIT_HASH build arg from the host where git
is available, ensuring the footer displays the real commit hash.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

deploy.sh

@@ -38,8 +38,9 @@ git reset --hard "origin/$BRANCH"
 echo "Updated to: $(git log --oneline -1)"
 
 # Rebuild containers
+export COMMIT_HASH=$(git rev-parse --short HEAD)
 echo ""
-echo "Rebuilding containers..."
+echo "Rebuilding containers (commit: $COMMIT_HASH)..."
 docker compose -p "$PROJECT_NAME" build --no-cache app
 
 if [[ "$BUILD_ONLY" == true ]]; then