fix(packaging): address Copilot review findings

Fix glob expansion in px4-gazebo.sh that could match multiple arch
directories by using find instead of shell glob. Add /tmp fallback
when HOME is unset in main.cpp to avoid writing to filesystem root.

Signed-off-by: Ramon Roche <mrpollo@gmail.com>

Author: mrpollo

Tools/packaging/px4-gazebo.sh

@@ -18,8 +18,8 @@ export GZ_SIM_SERVER_CONFIG_PATH="${PX4_GZ_SERVER_CONFIG}"
 # to the unversioned libgz-physics-dartsim-plugin.so. The runtime package only
 # ships versioned .so files; the unversioned symlink lives in the -dev package.
 # Create it if missing so Gazebo finds the DART engine without installing -dev.
-GZ_PHYSICS_ENGINE_DIR=$(echo /usr/lib/*/gz-physics-7/engine-plugins)
-if [ -d "$GZ_PHYSICS_ENGINE_DIR" ]; then
+GZ_PHYSICS_ENGINE_DIR=$(find /usr/lib -maxdepth 3 -type d -name "engine-plugins" -path "*/gz-physics-7/*" 2>/dev/null | head -1)
+if [ -n "$GZ_PHYSICS_ENGINE_DIR" ] && [ -d "$GZ_PHYSICS_ENGINE_DIR" ]; then
     UNVERSIONED="$GZ_PHYSICS_ENGINE_DIR/libgz-physics-dartsim-plugin.so"
     if [ ! -e "$UNVERSIONED" ]; then
         VERSIONED=$(ls "$GZ_PHYSICS_ENGINE_DIR"/libgz-physics*-dartsim-plugin.so.* 2>/dev/null | head -1)

platforms/posix/src/px4/common/main.cpp

@@ -276,7 +276,7 @@ int main(int argc, char **argv)
 
 			} else {
 				const char *home = getenv("HOME");
-				state_base = std::string(home ? home : "") + "/.local/share";
+				state_base = std::string(home ? home : "/tmp") + "/.local/share";
 			}
 
 			working_directory = state_base + "/px4/rootfs";