Renamed macro cache artifacts are resolved correctly

The storage fetch step no longer force-unwraps when the requested macro cache artifact is missing from the archive. Macros whose product name differs from the target name (e.g. DependenciesMacros stored as DependenciesMacrosPlugin) are now resolved through any matching single .macro artifact in the restored tree. Genuinely missing artifacts fall back to building from sources instead of producing a generated project that references an unusable artifact.