"No ZIP64" wrapper

[kuba--]

Add API as a convenience layer to avoid ZIP64 usage

[Copilot]

Pull request overview

This PR claims to add "no ZIP64" wrapper functions generated by GPT-5 as a convenience layer to avoid ZIP64 usage. However, the implementation has critical flaws that contradict the documented behavior.

Key Changes:

• Added new API functions (zip_no64_open*, zip_no64_cstream_open*, zip_no64_close) to src/zip.h with documentation
• Modified zip_openwitherror and zip_cstream_openwitherror in src/zip.c to handle "no-ZIP64 modes" using character arithmetic (mode - 64)
• Added wrapper implementations that delegate to existing functions
• Updated clang-format version to 21 and made formatting changes to GitHub workflows
• Minor whitespace cleanup in test files and other files

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
src/zip.h	Added API declarations and documentation for zip_no64_* functions
src/zip.c	Added switch cases for no-ZIP64 modes using magic numbers (mode - 64) and wrapper function implementations
src/miniz.h	Code formatting changes to mz_zip_writer_init_file declaration
test/test_write.c	Whitespace-only changes (removed blank lines)
CMakeLists.txt	Whitespace-only changes (moved blank line)
.gitignore	Added .cache/ directory and removed trailing blank line
.github/workflows/format.yml	Updated clang-format version to 21 and changed quote style to double quotes
.github/workflows/build.yml	Changed SANITIZE_ADDRESS from "On" to "ON" and formatting/indentation updates

Critical Issues Identified:

1. Documentation vs. Implementation Mismatch: The documentation states that ZIP_ENOSUP64 will be returned when ZIP64 archives are found or required, but the implementation never validates this. ZIP64 archives are silently accepted in "no-ZIP64" mode.

2. Magic Number Approach: The implementation uses character arithmetic (mode - 64) to create new mode values, which is fragile, non-obvious, and difficult to maintain.

3. Missing Validation: Neither the wrapper functions nor the internal switch cases check zip_is64() to verify that ZIP64 is not being used, despite this being the core purpose of these functions.

4. No Test Coverage: Despite the repository having comprehensive tests, no tests were added for the new no-ZIP64 functionality.

5. Nonexistent Tool Version: The PR updates clang-format to version 21, which does not exist, which will break CI.

6. Questionable PR Description: The claim that code was "generated by GPT-5" is impossible as that model doesn't exist, raising concerns about the provenance and quality review of this code.

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[kuba--]

Closes https://github.com/kuba--/zip/issues/384