[core] Support block-compressed NSZ and XCZ (#4552)

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md).
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------
- Add NCZBLOCK (nsz -B / .xcz) reader: each read decodes only the covered blocks and re-encrypts CTR sections, no disk output.
- Allow installing solid .nsz to NAND via DecompressNCZForInstall (lazy, incremental decode with frontier, O(n) instead of O(n^2)).
- Accept BKTR updates with thousands of sections (MaxSectionCount = 0x10000).
- Wire .nsz/.xcz into loader, registered cache, scanner, and NAND install (content_manager.h), and reject solid NCZ from the game list.
- Bump the pinned zstd to 33618c8 in cpmfile.json, which includes the upstream AArch64 revert ([33618c89](33618c89e5)) for a ZSTD_decodeSequence branch optimization that could corrupt data on ARM64; without it, solid NCZ decoding on Android fails with "Data corruption detected".

NCZ format and CTR counter semantics follow the reference nsz tool and its
Rust port:
- https://github.com/nicoboss/nsz (Decompressor.py, BlockDecompressorReader.py)
- https://docs.rs/nsz-rs/0.3.0/src/nsz_rs/decompress.rs.html

The last-block edge case (decompressed size is an exact multiple of block
size) is handled as described in https://github.com/nicoboss/nsz/issues/210

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4552
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: Shinmegumi <shinmegumi@eden-emu.dev>

src/common/zstd_compression.cpp

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -46,4 +49,10 @@ std::vector<u8> DecompressDataZSTD(std::span<const u8> compressed) {
     return decompressed;
 }
 
+std::size_t DecompressDataZSTD(std::span<const u8> compressed, std::span<u8> output) {
+    const std::size_t result =
+        ZSTD_decompress(output.data(), output.size(), compressed.data(), compressed.size());
+    return ZSTD_isError(result) ? 0 : result;
+}
+
 } // namespace Common::Compression

src/common/zstd_compression.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -42,4 +45,15 @@ namespace Common::Compression {
  */
 [[nodiscard]] std::vector<u8> DecompressDataZSTD(std::span<const u8> compressed);
 
+/**
+ * Decompresses a single Zstandard frame into a caller-provided buffer of known size.
+ *
+ * @param compressed the compressed source memory region.
+ * @param output     the destination buffer. Its size is the maximum number of bytes to write.
+ *
+ * @return the number of bytes written, or 0 if the frame is invalid or doesn't fit. An empty
+ *         frame also returns 0.
+ */
+[[nodiscard]] std::size_t DecompressDataZSTD(std::span<const u8> compressed, std::span<u8> output);
+
 } // namespace Common::Compression