Runner image: add xauth (xvfb-run requirement)

runner/Dockerfile

@@ -15,10 +15,15 @@ ENV DEBIAN_FRONTEND=noninteractive \
 # Wine (64-bit), node + git for JS actions, and build/package tooling.
 RUN apt-get update && apt-get install -y --no-install-recommends \
         ca-certificates curl wget unzip zip \
-        wine wine64 xvfb winetricks cabextract \
+        wine wine64 xvfb xauth cabextract \
         nodejs git \
     && apt-get clean && rm -rf /var/lib/apt/lists/*
 
+# winetricks (standalone script; not packaged in Debian main).
+RUN wget -qO /usr/local/bin/winetricks \
+      "https://raw.githubusercontent.com/Winetricks/winetricks/master/src/winetricks" \
+    && chmod +x /usr/local/bin/winetricks
+
 # Gitea Actions runner (linux-amd64 binary).
 RUN wget -qO /usr/local/bin/act_runner \
       "https://gitea.com/gitea/act_runner/releases/download/v0.6.1/act_runner-0.6.1-linux-amd64" \