Fix TarFactory extension hinting in TryOpenReader, TryOpenReaderAsync, and GetCompressionType

[Copilot]

TarFactory.IsArchive and GetCompressionType had no path to receive ReaderOptions, so ExtensionHint and custom Providers were silently dropped whenever Factory.TryOpenReader drove detection. Every call fell back to brute-forcing all TarWrapper candidates and the GZip probe lacked its CompressionContext.

Changes

TarFactory — override TryOpenReader / TryOpenReaderAsync

• TryOpenReader: replaces the base-class pattern of IsArchive → Rewind(true) → OpenReader with a direct wrapper loop that passes options.Providers and full ReaderOptions into CreateProbeDecompressionStream. Uses stream.Rewind(true) (not StopRecording()) to correctly reset both seekable (SeekableSharpCompressStream) and ring-buffer streams.
• TryOpenReaderAsync: wraps the incoming SharpCompressStream in a fresh ring-buffer SharpCompressStream before probing. This is required because decompressor constructors (e.g. LZipStream, XZStream) perform synchronous reads; the ring buffer lets those sync reads replay data that was fetched asynchronously — critical for async-only transports.

// Before: options.ExtensionHint was ignored, default providers were used
Factory.TryOpenReader → TarFactory.IsArchive(stream, password)  // no ReaderOptions

// After: hints and providers flow through the entire detection path
TarFactory.TryOpenReader(stream, options) → CreateProbeDecompressionStream(..., options)

TarFactory.GetCompressionType / GetCompressionTypeAsync

Added optional IReaderOptions? readerOptions = null parameter, threaded through to CreateProbeDecompressionStream / CreateProbeDecompressionStreamAsync.
For GetCompressionTypeAsync the new parameter is inserted before CancellationToken; all in-tree callers are updated.

TarArchive.Factory.cs

All GetCompressionType / GetCompressionTypeAsync call-sites now pass sourceStream.ReaderOptions, so archive-open paths also benefit from hint propagation.

Tests

Added TarReaderTests cases that open compressed tar archives via ReaderFactory.OpenReader with an explicit ExtensionHint (.tar.gz, .tar.bz2, .tar.xz, .tar), exercising the previously broken detection path.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Tar archive doesn't use extension hinting on two primary functions</issue_title>
<issue_description>The CreateProbeDecompressionStream is the only way hinting happens with tar currently. Unfortunately that requires the reader options parameter to be passed which it is not in:

• GetCompressionType
• IsArchive

IsArchive is once again in the code flow for auto detection on OpenReader but that quickly causes this stack:

 	SharpCompress.dll!SharpCompress.Archives.Tar.TarArchive.IsTarFile(System.IO.Stream stream) Line 222	C#
 	SharpCompress.dll!SharpCompress.Factories.TarFactory.IsArchive(System.IO.Stream stream, string password) Line 67	C#
 	SharpCompress.dll!SharpCompress.Factories.Factory.TryOpenReader(SharpCompress.IO.SharpCompressStream stream, SharpCompress.Readers.ReaderOptions options, out SharpCompress.Readers.IReader reader) Line 89	C#
>	SharpCompress.dll!SharpCompress.Readers.ReaderFactory.OpenReader(System.IO.Stream stream, SharpCompress.Readers.ReaderOptions options) Line 51	C#

As TryOpenReader is calling IsArchive and IsArchive doesn't have the ability to take reader options it loses hinting and goes back to brute forcing.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Tar archive doesn't use extension hinting on two primary functions #1254

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