Jbl/chunked prereq cleanups

[ptahmose]

Description

This PR contains preparatory changes and small API additions that are independent of the planned experimental chunked-compression work.

Summary of changes:

• Add CreateBitmapFromSubBlockData, a low-level helper for creating a bitmap directly from compressed subblock payload data and the required bitmap metadata.
• Refactor bitmap creation internals so decoding from an ISubBlock and decoding from raw subblock data can share the same implementation.
• Add AttachmentStatistics and GetAttachmentStatistics() support for attachment repositories.
• Improve unit-test registration for cross-compiling by using gtest_discover_tests() only when tests can be discovered by executing the test binary.
• Fix the Codecov workflow flag variable casing from matrix.OS to matrix.os.
• Switch CLI11 usage to the single-header include.
• Bump libCZI version to 0.68.0 and update the version history.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

• locally
• CI/CD

Checklist:

• I followed the Contributing Guidelines.
• I did a self-review.
• I commented my code, particularly in hard-to-understand areas.
• I updated the documentation.
• I updated the version of libCZI following Versioning of libCZI depending on the type of change
  • Bug fix -> PATCH
  • New feature -> MINOR
  • Breaking change -> MAJOR
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.

[Copilot]

Pull request overview

This PR introduces a couple of preparatory API additions and internal refactors intended to support upcoming experimental chunked-compression work, while also improving build/test integration and CI workflow correctness.

Changes:

• Added a low-level bitmap decode entry point (CreateBitmapFromSubBlockData) and refactored bitmap creation internals to share decoding logic.
• Added an attachment statistics API (AttachmentStatistics / GetAttachmentStatistics()), with implementations in reader and reader-writer.
• Improved CMake unit test registration for cross-compiling, updated Codecov flag casing, updated CLI11 usage/version, and bumped libCZI to 0.68.0.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
Src/libCZIAPI_UnitTests/CMakeLists.txt	Use gtest_discover_tests() when not cross-compiling.
Src/libCZI_UnitTests/CMakeLists.txt	Use gtest_discover_tests() when not cross-compiling.
Src/libCZI/libCZI.h	Add CreateBitmapFromSubBlockData, AttachmentStatistics, and GetAttachmentStatistics().
Src/libCZI/CreateBitmap.cpp	Refactor decoding helpers; implement CreateBitmapFromSubBlockData().
Src/libCZI/CZIReader.h	Declare GetAttachmentStatistics() override.
Src/libCZI/CZIReader.cpp	Implement GetAttachmentStatistics() for the reader.
Src/libCZI/CziReaderWriter.h	Declare GetAttachmentStatistics() override.
Src/libCZI/CziReaderWriter.cpp	Implement GetAttachmentStatistics() for the reader-writer.
Src/libCZI/CziAttachmentsDirectory.h	Add GetAttachmentCount() to attachment directory.
Src/libCZI/CziAttachmentsDirectory.cpp	Implement GetAttachmentCount().
Src/CZICmd/cmdlineoptions.cpp	Switch CLI11 includes to single-header CLI/CLI.hpp.
Src/CZICmd/CMakeLists.txt	Bump CLI11 FetchContent tag to v2.6.2.
.github/workflows/cmake.yml	Fix Codecov flag variable casing to matrix.os.
CMakeLists.txt	Bump project version to 0.68.0.
docs/source/pages/version_history.md	Add 0.68.0 version history entry.

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[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 5 comments.

[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (1)

Src/libCZI_UnitTests/test_reader.cpp:1611

• CreateBitmapFromSubBlockData() now explicitly throws std::invalid_argument when pv == nullptr, but the new unit tests don’t cover this contract. Adding a small regression test would help ensure callers keep getting a clear exception instead of a potential codec-level crash if this guard changes later.

    for (int y = 1; y < 4; ++y)
    {
        bitmap_pointer = static_cast<const uint8_t*>(locked_bitmap.ptrDataRoi) + static_cast<size_t>(y) * locked_bitmap.stride;
        for (int x = y == 1 ? 2 : 0; x < 4; ++x)
        {
            EXPECT_EQ(bitmap_pointer[x], 0);
        }
    }
}

[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated no new comments.

[codecov]

Codecov Report

❌ Patch coverage is 94.28571% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 66.63%. Comparing base (b85521a) to head (03e1821).

Files with missing lines	Patch %	Lines
Src/libCZI/CreateBitmap.cpp	93.47%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #171      +/-   ##
==========================================
+ Coverage   66.47%   66.63%   +0.15%     
==========================================
  Files          96       96              
  Lines       12365    12402      +37     
==========================================
+ Hits         8220     8264      +44     
+ Misses       4145     4138       -7     

Flag	Coverage Δ
windows-latest	66.63% <94.28%> (+0.15%)	⬆️

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