refactor(compression): Unify compression APIs with libarchive backend

[HTRamsey]

Summary

Replace fragmented compression utilities (QGCLZMA, QGCZlib, QGCZip) with a unified QGCCompression interface backed by libarchive.

Changes

New Unified API

• QGCCompression namespace with format detection and unified operations
• QGClibarchive for ZIP archive operations via libarchive
• Support for GZIP, XZ, ZSTD, ZIP, TAR formats with auto-detection

Compression Library Stack (via CPM)

Library	Version	Purpose
zlib-ng	2.3.2	Optimized zlib replacement
xz/liblzma	5.8.2	LZMA/XZ compression
zstd	1.5.7	Zstandard compression
lz4	1.10.0	Fast compression
bzip2	1.1.0	Bzip2 compression
libarchive	3.8.4	Archive handling

API Simplification

// Old API - multiple modules, manual format handling
if (fileName.endsWith(".lzma") || fileName.endsWith(".xz")) {
    QGCLZMA::inflateLZMAFile(fileName, outputFileName);
} else if (fileName.endsWith(".gz")) {
    QGCZlib::inflateGzipFile(fileName, outputFileName);
}

// New API - unified, auto-detecting
QString output = QGCCompression::decompressIfNeeded(fileName);

Removed

• QGCLZMA module (replaced by QGCCompression)
• QGCZlib module (replaced by QGCCompression)
• QGCZip module (replaced by QGClibarchive)
• Duplicate test files (consolidated into QGCCompressionTest)

Test Plan

• QGCCompressionTest passes (10 tests)
  • Format detection (extension and magic bytes)
  • ZIP roundtrip with nested directories and empty files
  • ZIP extraction from Qt resources
  • GZIP and LZMA decompression
• Build succeeds on Linux
• Build verification on Windows/macOS/Android/iOS

[Copilot]

Pull request overview

This PR refactors QGroundControl's compression utilities by replacing three separate modules (QGCLZMA, QGCZlib, QGCZip) with a unified QGCCompression API backed by libarchive. The changes introduce automatic format detection, support for multiple compression formats (GZIP, XZ, ZSTD, ZIP, TAR variants), and consolidate the dependency management through CPM.

Key Changes

• Introduced unified QGCCompression namespace with format detection and single API for all compression operations
• Added QGClibarchive wrapper for ZIP archive operations using libarchive instead of Qt's private QZipWriter/QZipReader
• Integrated 6 compression libraries (zlib-ng, xz/liblzma, zstd, lz4, bzip2, libarchive) via CPM with proper dependency configuration

Reviewed changes

Copilot reviewed 22 out of 22 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
src/Utilities/Compression/QGCCompression.h	New unified compression API header with format detection and operations for single-file and archive compression
src/Utilities/Compression/QGCCompression.cc	Implementation of unified compression API with libarchive-based decompression for GZIP, XZ, ZSTD formats
src/Utilities/Compression/QGClibarchive.h	Header for libarchive-based ZIP archive operations
src/Utilities/Compression/QGClibarchive.cc	Implementation of ZIP creation/extraction with Qt resource support and security checks
src/Utilities/Compression/CMakeLists.txt	Build configuration for 6 compression libraries with CPM integration and cross-library compatibility setup
src/Utilities/Compression/QGCLZMA.{h,cc}	Removed - replaced by QGCCompression
src/Utilities/Compression/QGCZlib.{h,cc}	Removed - replaced by QGCCompression
src/Utilities/Compression/QGCZip.{h,cc}	Removed - replaced by QGClibarchive
src/Vehicle/VehicleSetup/FirmwareUpgradeController.cc	Updated to use QGCCompression::decompressFile() instead of QGCZlib::inflateGzipFile()
src/Vehicle/ComponentInformation/ComponentInformationTranslation.cc	Simplified decompression logic using QGCCompression::decompressIfNeeded()
src/Vehicle/ComponentInformation/ComponentInformationManager.cc	Simplified decompression logic using QGCCompression::decompressIfNeeded()
src/Camera/VehicleCameraControl.cc	Replaced manual LZMA decompression with QGCCompression::decompressIfNeeded()
test/Utilities/Compression/QGCCompressionTest.{h,cc}	New comprehensive test suite with 10 tests for format detection, ZIP operations, and single-file decompression
test/Utilities/Compression/DecompressionTest.{h,cc}	Removed - consolidated into QGCCompressionTest
test/Utilities/Compression/CMakeLists.txt	Updated to reference new test files
test/UnitTestList.cc	Updated test registration from DecompressionTest to QGCCompressionTest
test/CMakeLists.txt	Updated test name reference

[Copilot]

The test creates temporary directories but doesn't verify that cleanup happened correctly. The QTemporaryDir destructor should handle cleanup, but if tests fail midway, it's good practice to verify the directories are cleaned up. Additionally, the test doesn't check that the temporary directories are actually deleted after cleanup() is called.

[Copilot]

Pull request overview

Copilot reviewed 102 out of 109 changed files in this pull request and generated no new comments.