cursor-agent: ensure libz.so.1 is loaded

[shebpamm]

Summary

Despite #4264, cursor-agent still fails with the following currently:

Error: node-loader:
Error: libz.so.1: cannot open shared object file: No such file or directory

The dependency comes from the following node-loader module:

$ nix build .#cursor-agent
$ ldd result/file_service.linux-x64-gnu.node
        linux-vdso.so.1 (0x000074a14c595000)
        libz.so.1 => not found
        libgcc_s.so.1 => /nix/store/g54b6ghpnn98hfdz4yqw87w10c3hx8bv-xgcc-15.2.0-libgcc/lib/libgcc_s.so.1 (0x000074a14c560000)
        libpthread.so.0 => /nix/store/57iz36553175g3178pvxjij8z5rcsd4n-glibc-2.42-61/lib/libpthread.so.0 (0x000074a14c55b000)
        libm.so.6 => /nix/store/57iz36553175g3178pvxjij8z5rcsd4n-glibc-2.42-61/lib/libm.so.6 (0x000074a14c463000)
        libdl.so.2 => /nix/store/57iz36553175g3178pvxjij8z5rcsd4n-glibc-2.42-61/lib/libdl.so.2 (0x000074a14c45e000)
        libc.so.6 => /nix/store/57iz36553175g3178pvxjij8z5rcsd4n-glibc-2.42-61/lib/libc.so.6 (0x000074a14aa00000)
        /nix/store/57iz36553175g3178pvxjij8z5rcsd4n-glibc-2.42-61/lib64/ld-linux-x86-64.so.2 (0x000074a14c597000)

What I've done is add libz.so.1 to wrapBuddyExtraNeeded, and this seems to fix the issue.

Extra thought: I'm not sure if wrap-buddy could wrap the module itself but it would be nice, since now this is prone to break if a node-loader module gets new dependencies.

Test plan

• nix build .#<package> succeeds
• Package updates via nix-update or has a custom update.py if nix-update doesn't work