Add Onimusha Way of the Sword (oniws) support

[Namsku]

Add Onimusha: Way of the Sword (oniws) support

Vendors the two oniws data files and wires the new game in as first-class support: .scn.21, .user.3, .pfb.18 (RSZ v16) and .msg.23 (version-parametric MSG) all parse/read/edit/write.

Vendored data (pinned upstreams)

Vendored file	Upstream source	SHA-256
src/reeutils/data/rszoniws.json.gz	seifhassine/REasy rszoniwots.json @ 2401f18bbe38c9db7eae1b8101af0e8905d4accd	75A04960E37CB44158D94E55C2B58FD75A51575F8134C8F258FBD7CF1AE39B2E
src/reeutils/data/paklist.oniws.txt.gz	kagenocookie/REE-Lib-Resources oniws/oniws_files.list @ 6776919a1a03b1f980761004b8b303f37ce60d9b	29555421B4C132CE72E8217B71DBCC3DF8E4F5173CFC36D7A96A8EE5EA83B5B0

Changes

• Data: rszoniws.json.gz (RSZ type repo) + paklist.oniws.txt.gz (133,012 paths) embedded under data/; game registered automatically via the GetSupportedGamesCore() resource-convention intersection.
• Empty templates for the import/write path: empty.scn.21 (128 B), empty.user.3 (112 B), empty.pfb.18 (128 B) — generated from real retail files, all RSZ v16; CLI export→import round-trips byte-identical.
• Registration: ree-engine-details.md supported-games list, GameNames.ONIWS = "oniws", OriginalPakHelper oniws arms (OnimushaWotS install dir, rszoniws repo).
• Tests: TestOniws.cs (6 tests — type-repo smoke + corpus round-trips against the retail install), TestOniwsRegistration.cs (4 tests — supported-game registration, embedded data, empty templates, RSZ v16 parse).
• Docs/CLI polish: README Supported-formats row + .fsmv2.42 read-only note; Program.cs find/tree examples.

Verification results

• dotnet build src/reeutils/reeutils.csproj -c Release — 0 warnings
• dotnet build test/IntelOrca.Biohazard.REE.Tests -c Release — 0 warnings
• REE.Tests full suite: 64 passed, 68 skipped, 0 failed (skips = paks not installed, expected)
• TestOniws: 6/6 passed (with STEAM_DIR=E:\Steam\steamapps\common)
• TestOniwsRegistration: 4/4 passed
• find --pak <retail pak> -g oniws "natives/stm/**/*.scn.21" → 14,169 matches, 0 "No file name found" (100% hash resolution)
• inspect ACE_SAVE_MSG.msg.23 → File type: MSG / Version: 23 / Entries: 28
• tree --json Area.scn.21 → valid JSON with resolved app.* type names (e.g. via.GameObject)

Known caveats (documented, not fixed)

• .fsmv2.42 files (1,539 in pak) can be read but .fsmv2 import is unsupported for this version — documented in README.
• app.EventLightConstraintSetter tree dump incomplete — upstream REasy day-one dump incompleteness.
• Pre-existing, unrelated: 3 REEUtils.Tests failures (TestBhvt ×2, TestFixModifier ×1) reproduce identically on base commit e97eceb, before this branch.

[Namsku]

Fix: JSON import of .scn.21\ scene files (follow-up commit 03a6b98)

The export->import JSON round-trip on oniws .scn.21\ failed with \Unsupported RSZ value type 'Data'. Root cause: \RszFieldType.Data\ — a raw byte-blob field type used by \�ia.Folder/value data — was read as base64 in the binary reader and written as base64 by the JSON exporter, but the importer had no mapping for it.

Fix: register \RszFieldType.Data\ in \s_rawValueTypes\ so \ReadValue\ decodes the base64 payload, and map it to \�yte[]\ in \GetValueClrType\ for legacy dumps. This is additive and only unblocks imports.

Verified:

• \TestOniws\ 7/7 green including new \Rebuild_Oniws_Scene_Json_RoundTrip\ regression test.
• \TestRszSerialization\ + scene/user/pfb/msg/file-handler suites green (65 tests).
• CLI: \�xport\ → edit JSON → \import\ → re-\�xport\ on \Area.scn.21\ is JSON-identical; imported tree matches the native binary rebuild byte-for-byte.

So all four oniws formats are now editable end-to-end: .user.3\ ✅ .msg.23\ ✅ .pfb.18\ ✅ .scn.21\ ✅ (was the last blocker).