Moves dockerfile and prepares for signed commits

ci/Dockerfile.ci

@@ -0,0 +1,24 @@
+FROM ubuntu:26.04
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+      python3 \
+      clang-format \
+      cmake \
+      ninja-build \
+      git \
+      g++ \
+      make \
+      ca-certificates \
+      openssh-client \
+      pkg-config \
+      qtbase5-dev \
+      qt6-base-dev \
+      qt6-base-dev-tools \
+      qt6-tools-dev \
+      qt6-tools-dev-tools && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /workspace