chore: import upstream snapshot with attribution

pkg/zlib/build.zig

@@ -0,0 +1,77 @@
+const std = @import("std");
+
+pub fn build(b: *std.Build) !void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const lib = b.addLibrary(.{
+        .name = "z",
+        .root_module = b.createModule(.{
+            .target = target,
+            .optimize = optimize,
+        }),
+        .linkage = .static,
+    });
+    lib.linkLibC();
+    if (target.result.os.tag.isDarwin()) {
+        const apple_sdk = @import("apple_sdk");
+        try apple_sdk.addPaths(b, lib);
+    }
+
+    if (b.lazyDependency("zlib", .{})) |upstream| {
+        lib.addIncludePath(upstream.path(""));
+        lib.installHeadersDirectory(
+            upstream.path(""),
+            "",
+            .{ .include_extensions = &.{".h"} },
+        );
+
+        var flags: std.ArrayList([]const u8) = .empty;
+        defer flags.deinit(b.allocator);
+        try flags.appendSlice(b.allocator, &.{
+            "-DHAVE_SYS_TYPES_H",
+            "-DHAVE_STDINT_H",
+            "-DHAVE_STDDEF_H",
+        });
+        if (target.result.abi == .msvc) {
+            try flags.appendSlice(b.allocator, &.{
+                "-fno-sanitize=undefined",
+                "-fno-sanitize-trap=undefined",
+            });
+        }
+        if (target.result.os.tag != .windows) {
+            try flags.append(b.allocator, "-DZ_HAVE_UNISTD_H");
+        }
+        if (target.result.abi == .msvc) {
+            try flags.appendSlice(b.allocator, &.{
+                "-D_CRT_SECURE_NO_DEPRECATE",
+                "-D_CRT_NONSTDC_NO_DEPRECATE",
+            });
+        }
+        lib.addCSourceFiles(.{
+            .root = upstream.path(""),
+            .files = srcs,
+            .flags = flags.items,
+        });
+    }
+
+    b.installArtifact(lib);
+}
+
+const srcs: []const []const u8 = &.{
+    "adler32.c",
+    "compress.c",
+    "crc32.c",
+    "deflate.c",
+    "gzclose.c",
+    "gzlib.c",
+    "gzread.c",
+    "gzwrite.c",
+    "inflate.c",
+    "infback.c",
+    "inftrees.c",
+    "inffast.c",
+    "trees.c",
+    "uncompr.c",
+    "zutil.c",
+};

pkg/zlib/build.zig.zon

@@ -0,0 +1,16 @@
+.{
+    .name = .zlib,
+    .version = "1.3.1",
+    .fingerprint = 0x73887d3aef823f9e,
+    .paths = .{""},
+    .dependencies = .{
+        // madler/zlib
+        .zlib = .{
+            .url = "https://deps.files.ghostty.org/zlib-1220fed0c74e1019b3ee29edae2051788b080cd96e90d56836eea857b0b966742efb.tar.gz",
+            .hash = "N-V-__8AAB0eQwD-0MdOEBmz7intriBReIsIDNlukNVoNu6o",
+            .lazy = true,
+        },
+
+        .apple_sdk = .{ .path = "../apple-sdk" },
+    },
+}