refactor UAB

[ComixHe]

No description provided.

[Copilot]

Pull Request Overview

This PR refactors the UAB by removing several obsolete OCI configuration generator files and updating multiple components across the UAB packager, loader, and header. Key changes include the deletion of numerous legacy generator source/header files, refactoring of filesystem/stat API usage in the packager code, and substantial updates to error handling and process termination in the UAB loader/main code.

Reviewed Changes

Copilot reviewed 29 out of 29 changed files in this pull request and generated 1 comment.

File	Description
libs/oci-cfg-generators/src/linglong/oci-cfg-generators/20_devices.cpp	Replaces old stat-based filesystem checks with statvfs, and now compares f_fsid fields.
libs/linglong/src/linglong/package/uab_packager.cpp	Introduces a new prepareSymlink function and updates error handling and symlink resolution logic.
apps/uab/loader/src/main.cpp and apps/uab/header/*	Updates include paths, process termination behavior, and memory allocation in digest calculation, along with various error-handling improvements.

Comments suppressed due to low confidence (2)

libs/oci-cfg-generators/src/linglong/oci-cfg-generators/20_devices.cpp:527

• Using f_fsid instead of st_dev for filesystem comparison is a significant change; please verify that this comparison correctly determines filesystem identity on all target platforms.

const bool shouldCopy = moduleFilesDirStat.f_fsid != filesStat.f_fsid;

apps/uab/header/src/main.cpp:126

• Using aligned allocation with ::operator new is appropriate, but please ensure that the chosen alignment (derived from the system page size) is portable and correctly meets all requirements on target platforms.

auto *buf = ::operator new(chunkSize, alignment, std::nothrow);