fix: avoid arm64/amd64 -dev header conflicts, generate missing .pc files for zmq/psl

scripts/build.sh

@@ -46,6 +46,8 @@ if command -v apt-get > /dev/null 2>&1; then
     binutils-aarch64-linux-gnu
 
   # aarch64 dev libraries (provides the .pc files pkg-config needs)
+  # Note: packages that conflict with their amd64 -dev counterparts (shared headers)
+  # are installed as runtime-only :arm64 — the .so + .pc files are still present.
   DEBIAN_FRONTEND=noninteractive apt-get install -y \
     libmpg123-dev:arm64 libsndfile1-dev:arm64 libopenal-dev:arm64 libassimp-dev:arm64 \
     libglew-dev:arm64 libglfw3-dev:arm64 liburiparser-dev:arm64 \
@@ -56,7 +58,31 @@ if command -v apt-get > /dev/null 2>&1; then
     libxrandr-dev:arm64 libxinerama-dev:arm64 libxcursor-dev:arm64 libxi-dev:arm64 \
     libpulse-dev:arm64 libudev-dev:arm64 libfreeimage-dev:arm64 \
     freeglut3-dev:arm64 libxxf86vm-dev:arm64 \
-    libcairo2-dev:arm64 libzmq3-dev:arm64
+    libcairo2-dev:arm64
+
+  # These conflict with amd64 -dev headers; install runtime-only for .so + .pc
+  DEBIAN_FRONTEND=noninteractive apt-get install -y \
+    libzmq5:arm64 libpsl5:arm64 || true
+  # Repair any partially-broken state from conflicts
+  apt-get -f install -y
+
+  # Generate minimal .pc files for runtime-only arm64 packages that lack one
+  if [ ! -f /usr/lib/aarch64-linux-gnu/pkgconfig/libzmq.pc ]; then
+    ZMQ_VER=$(dpkg -l libzmq5:arm64 2>/dev/null | awk '/^ii/{print $3}' | cut -d- -f1 || echo "4.3.5")
+    mkdir -p /usr/lib/aarch64-linux-gnu/pkgconfig
+    cat > /usr/lib/aarch64-linux-gnu/pkgconfig/libzmq.pc <<EOF
+prefix=/usr
+exec_prefix=\${prefix}
+libdir=\${prefix}/lib/aarch64-linux-gnu
+includedir=\${prefix}/include
+
+Name: libzmq
+Description: ZeroMQ messaging library
+Version: $ZMQ_VER
+Libs: -L\${libdir} -lzmq
+Cflags: -I\${includedir}
+EOF
+  fi
 fi
 
 # Install Node.js if missing