snapshot: preserve the uncommitted Canary instrumentation (not authored here)

Working-tree snapshot taken 2026-07-28 so this work is not lost. To be clear
about provenance: NONE of this was written in the session that committed it —
it is pre-existing uncommitted work on phase-a-tracing, last committed 2026-07-09,
from the xenia-rs decoder/deadlock investigation. It is recorded verbatim, not
reviewed and not tested.

Contents: 24 tracked modifications (ppc_emit_memory, xex_module, object_table,
shim_utils, xboxkrnl threading/rtl, xevent/xobject/xthread, memory) plus the
untracked probe sources audit_68_host_mem_watch, audit_69_event_signal_watch,
audit_70_semaphore_release_watch, phase_b_snapshot, and cmake/toolchains.

Deliberately excluded: build-cross/ (51 GB of build output) and
vkd3d-proton.cache. Note third_party/snappy is a submodule pointer change whose
target may not be pushed anywhere, so this branch is a preservation record rather
than a guaranteed-buildable tree.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CMakePresets.json

@@ -39,6 +39,22 @@
       "cacheVariables": {
         "CMAKE_SYSTEM_PROCESSOR": "ARM64"
       }
+    },
+    {
+      "name": "cross-win-clangcl",
+      "displayName": "Cross (Linux->Win MSVC) clang-cl + xwin",
+      "generator": "Ninja Multi-Config",
+      "binaryDir": "${sourceDir}/build-cross",
+      "toolchainFile": "${sourceDir}/cmake/toolchains/linux-to-win-msvc.cmake",
+      "condition": {
+        "type": "notEquals",
+        "lhs": "${hostSystemName}",
+        "rhs": "Windows"
+      },
+      "cacheVariables": {
+        "XWIN_DIR": "$env{HOME}/.xwin/splat",
+        "FXC_PATH": "$env{HOME}/.local/share/xenia-cross/fxc/fxc.exe"
+      }
     }
   ],
   "buildPresets": [
@@ -89,6 +105,21 @@
       "name": "vs-arm64-checked",
       "configurePreset": "vs-arm64",
       "configuration": "Checked"
+    },
+    {
+      "name": "cross-debug",
+      "configurePreset": "cross-win-clangcl",
+      "configuration": "Debug"
+    },
+    {
+      "name": "cross-release",
+      "configurePreset": "cross-win-clangcl",
+      "configuration": "Release"
+    },
+    {
+      "name": "cross-checked",
+      "configurePreset": "cross-win-clangcl",
+      "configuration": "Checked"
     }
   ]
 }