Update .gitignore to exclude build/packages directory and fix package build script output paths

.gitignore

@@ -48,3 +48,4 @@ schema/
 **/scenario.json
 scenario.json
 logs
+build/packages/

build-linux-packages.sh

@@ -216,7 +216,7 @@ if [ "$BUILD_DEB" = true ]; then
         --after-remove "${PROJECT_ROOT}/scripts/debian/postrm.sh" \
         -C "$PUBLISH_DIR" \
         -p "$DEB_OUTPUT" \
-        opt/=opt/jellyfin > "$DEB_LOG" 2>&1; then
+        .=opt/jellyfin > "$DEB_LOG" 2>&1; then
         print_success "Created: jellyfin-${VERSION}-amd64.deb"
         DEB_SIZE=$(du -h "$DEB_OUTPUT" | cut -f1)
         print_info "Size: $DEB_SIZE"
@@ -255,7 +255,7 @@ if [ "$BUILD_RPM" = true ]; then
         --after-remove "${PROJECT_ROOT}/scripts/redhat/postun.sh" \
         -C "$PUBLISH_DIR" \
         -p "$RPM_OUTPUT" \
-        opt/=opt/jellyfin > "$RPM_LOG" 2>&1; then
+        .=opt/jellyfin > "$RPM_LOG" 2>&1; then
         print_success "Created: jellyfin-${VERSION}-1.x86_64.rpm"
         RPM_SIZE=$(du -h "$RPM_OUTPUT" | cut -f1)
         print_info "Size: $RPM_SIZE"