fix: build-linux.sh --local cd to project root before building

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

warzone/scripts/build-linux.sh

@@ -438,6 +438,13 @@ do_local_deps() {
 }
 
 do_local_build() {
+  # cd to project root (script may be run from scripts/ or project root)
+  local script_dir
+  script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+  local project_root="$(dirname "$script_dir")"
+  cd "$project_root"
+  echo "       Project root: $(pwd)"
+
   local arch
   arch=$(uname -m)
   local os