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>

src/common/archive.h

@@ -0,0 +1,50 @@
+#ifndef KYTY_COMMON_ARCHIVE_H_
+#define KYTY_COMMON_ARCHIVE_H_
+
+#include "common/file.h"
+
+#include <cstdint>
+#include <filesystem>
+#include <memory>
+#include <vector>
+
+namespace Common {
+
+class ArchiveReader;
+
+class ArchiveFile {
+public:
+	~ArchiveFile();
+
+	[[nodiscard]] uint64_t Size() const;
+	[[nodiscard]] uint64_t Tell() const;
+	bool                   Seek(uint64_t offset);
+	void                   Read(void* data, uint32_t size, uint32_t* bytes_read);
+
+	KYTY_CLASS_NO_COPY(ArchiveFile);
+
+private:
+	struct Private;
+	explicit ArchiveFile(std::unique_ptr<Private> p);
+	std::unique_ptr<Private> m_p;
+
+	friend std::unique_ptr<ArchiveFile> OpenArchiveFile(const std::filesystem::path& path);
+};
+
+// Virtual paths use "archive.ext!/member" and retain native host-path encoding.
+[[nodiscard]] std::filesystem::path       MakeArchivePath(const std::filesystem::path& archive,
+                                                          const std::filesystem::path& member = {});
+[[nodiscard]] bool                        IsSupportedArchive(const std::filesystem::path& path);
+[[nodiscard]] bool                        IsArchivePath(const std::filesystem::path& path);
+[[nodiscard]] std::optional<File::Info>   GetArchiveInfo(const std::filesystem::path& path);
+[[nodiscard]] std::vector<File::DirEntry> GetArchiveDirEntries(const std::filesystem::path& path);
+[[nodiscard]] std::filesystem::path       GetArchiveHostPath(const std::filesystem::path& path);
+[[nodiscard]] std::unique_ptr<ArchiveFile> OpenArchiveFile(const std::filesystem::path& path);
+
+// Retain this handle while a mount or metadata scan is active to reuse the index and block cache.
+// Accepts either a host archive filename or a virtual path inside the archive.
+[[nodiscard]] std::shared_ptr<ArchiveReader> OpenArchive(const std::filesystem::path& path);
+
+} // namespace Common
+
+#endif /* KYTY_COMMON_ARCHIVE_H_ */