Zarchive Loading (#724)

* Simplify archive loading and harden filesystem integration

* Restore directory entry name length assertion

* Keep graphics-dependent filesystem tests out of CI

---------

Co-authored-by: nmzik <Nmzik@mail.ru>

tests/ArchiveTestFixture.h

@@ -0,0 +1,66 @@
+#pragma once
+
+#include <cstdint>
+#include <filesystem>
+#include <fstream>
+#include <span>
+#include <string>
+#include <string_view>
+#include <zarchive/zarchivewriter.h>
+
+namespace ArchiveTests {
+
+inline constexpr std::string_view Eboot = "ELF fixture";
+inline constexpr std::string_view Param =
+    R"({"titleId":"TEST00001","titleName":"Archive Test"})";
+inline constexpr std::string_view UnicodeFilename =
+    "asset-\xc3\xa9-\xe6\x97\xa5\xe6\x9c\xac\xe8\xaa\x9e.bin";
+inline const std::string LongFilename = std::string(160, 'a') + ".bin";
+
+// Both Common::File and guest filesystem tests read the same archive layout.
+inline bool CreateArchive(const std::filesystem::path &path,
+                          std::span<const uint8_t> payload) {
+  struct Output {
+    std::filesystem::path path;
+    std::ofstream stream;
+    bool good = true;
+  } output{.path = path};
+  {
+    ZArchiveWriter writer(
+        [](int32_t, void *opaque) {
+          auto &out = *static_cast<Output *>(opaque);
+          out.stream.open(out.path, std::ios::binary | std::ios::trunc);
+          out.good = out.stream.is_open();
+        },
+        [](const void *data, size_t size, void *opaque) {
+          auto &out = *static_cast<Output *>(opaque);
+          out.stream.write(static_cast<const char *>(data),
+                           static_cast<std::streamsize>(size));
+          out.good = out.good && out.stream.good();
+        },
+        &output);
+    if (!output.good || !writer.MakeDir("sce_sys", true) ||
+        !writer.MakeDir("assets/subdir", true)) {
+      return false;
+    }
+    const auto add = [&](std::string_view name, const void *data, size_t size) {
+      if (!writer.StartNewFile(name.data())) {
+        return false;
+      }
+      writer.AppendData(data, size);
+      return true;
+    };
+    if (!add("eboot.bin", Eboot.data(), Eboot.size()) ||
+        !add("sce_sys/param.json", Param.data(), Param.size()) ||
+        !add("assets/subdir/data.bin", payload.data(), payload.size()) ||
+        !add(UnicodeFilename, Eboot.data(), Eboot.size()) ||
+        !add(LongFilename, Eboot.data(), Eboot.size())) {
+      return false;
+    }
+    writer.Finalize();
+  }
+  output.stream.close();
+  return output.good && !output.stream.fail();
+}
+
+} // namespace ArchiveTests