Seems to be fully statically built now.

source/Dockerfile

@@ -0,0 +1,34 @@
+FROM alpine:latest
+
+# Install build dependencies
+RUN apk add --no-cache \
+    build-base \
+    cmake \
+    git \
+    musl-dev \
+    curl \
+    bash \
+    musl \
+    g++ \
+    ninja \
+    linux-headers
+
+# Set working directory
+WORKDIR /build
+
+# Copy source files
+COPY . .
+
+# Configure and build
+RUN mkdir -p build_static
+
+RUN cmake -G Ninja -B build_static -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_C_COMPILER=gcc \
+    -DCMAKE_CXX_COMPILER=g++ \
+    -DCMAKE_EXE_LINKER_FLAGS="-static" \
+    -DCMAKE_FIND_LIBRARY_SUFFIXES=".a" \
+    -DBUILD_SHARED_LIBS=OFF
+
+RUN cmake --build build_static
+
+# The resulting binary will be in build_static/dropshell