Fix Mac build failure with zlib static library detection

[Copilot]

This PR fixes the Mac build failure where cargo build would fail with:

error: could not find native static library `zlib`, perhaps an -L flag is missing?

The issue was caused by multiple problems in the zlib-ng build process:

1. Silent CMake failures: The build script didn't check for CMake errors, so compilation issues in zlib-ng's test suite would cause silent failures
2. Library naming inconsistencies: Different zlib-ng configurations produce different library names (libz.a, libzlib.a, or libz-ng.a), but the build script always tried to link with zlib
3. Test compilation issues: Building all targets included problematic test code that failed on some zlib-ng versions

Changes Made

Enhanced error handling: Added proper error checking for both CMake configure and build steps with descriptive panic messages to help diagnose issues.

Dynamic library detection: The build script now automatically detects which zlib library was actually built and links appropriately:

// Check for different possible library names
let possible_libs = ["libz.a", "libzlib.a", "libz-ng.a"];
// ... detect and link with the correct one

Target-specific builds: Only build the zlib target to avoid test compilation failures that can prevent library creation.

Improved Mac support: Explicitly force static builds and ensure proper architecture flags are set for both Intel and Apple Silicon Macs.

The fix makes the build process robust across different platforms and zlib-ng configurations, ensuring that the "could not find native static library" error is resolved by adapting to whatever library is actually produced.

Fixes #12.

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