Fix clang-cl ASan preset setup

CMakeLists.txt

@@ -9,11 +9,14 @@ if(POLICY CMP0091)
     cmake_policy(SET CMP0091 NEW)
 endif()
 
-set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")
-
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
 
 include(PanoPainterOptions)
+if(PP_ENABLE_ASAN AND MSVC AND CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreadedDLL")
+else()
+    set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")
+endif()
 include(PanoPainterWarnings)
 include(PanoPainterSources)
 include(PanoPainterVersion)

CMakePresets.json

@@ -57,13 +57,13 @@
     },
     {
       "name": "windows-clangcl-asan",
-      "inherits": "base",
+      "inherits": "platform-headless-base",
       "displayName": "Windows clang-cl ASan",
       "generator": "Ninja",
-      "toolset": "ClangCL",
       "cacheVariables": {
         "CMAKE_C_COMPILER": "clang-cl",
         "CMAKE_CXX_COMPILER": "clang-cl",
+        "CMAKE_MSVC_RUNTIME_LIBRARY": "MultiThreadedDLL",
         "PP_ENABLE_ASAN": "ON",
         "PP_ENABLE_UBSAN": "OFF"
       }

docs/modernization/build-inventory.md

@@ -72,6 +72,7 @@ ctest --preset desktop-fast-vcpkg --build-config Debug
 cmake --preset android-arm64
 powershell -ExecutionPolicy Bypass -File scripts\automation\platform-build.ps1 -Presets android-arm64
 powershell -ExecutionPolicy Bypass -File scripts\automation\package-smoke.ps1 -Preset windows-msvc-default -Configuration Debug
+cmake --fresh --preset windows-clangcl-asan
 ```
 
 Known local toolchain state:
@@ -82,6 +83,9 @@ Known local toolchain state:
   (`vcpkg version` reports 2025-11-19)
 - Android SDK: `C:\Users\omara\AppData\Local\Android\Sdk`
 - Android NDK: `C:\Users\omara\AppData\Local\Android\Sdk\ndk\29.0.14206865`
+- clang-cl: `C:\Program Files\LLVM\bin\clang-cl.exe` reports 18.1.8, but the
+  selected VS 2026-preview STL expects Clang 20 or newer; see DEBT-0014 before
+  treating `windows-clangcl-asan` as a passing sanitizer gate.
 - Android arm64 headless configure/build passes through root CMake and the
   `platform-build` automation wrapper for `pp_foundation`, `pp_assets`,
   `pp_paint`, `pp_document`, `pp_renderer_api`, `pp_paint_renderer`,

docs/modernization/debt.md

@@ -32,6 +32,7 @@ agent or engineer to remove them without reconstructing context from chat.
 | DEBT-0011 | Open | Modernization | `package-smoke` validates the Windows CMake app artifact only, not AppX/APK/Apple/WebGL package outputs | Platform package targets are not migrated to root CMake yet | `powershell -ExecutionPolicy Bypass -File scripts\automation\package-smoke.ps1 -Preset windows-msvc-default -Configuration Debug` | Package-smoke covers Windows AppX, Android APK variants, Apple bundles, and WebGL output where local toolchains are present |
 | DEBT-0012 | Open | Modernization | `pp_ui_core` uses vcpkg tinyxml2 on `windows-msvc-vcpkg-headless`, but retains `pp_vendor_tinyxml2` for default and unproven platform presets | Mobile/AppX/Apple triplets and app packaging still need validation before removing the vendored fallback | `ctest --preset desktop-fast-vcpkg --build-config Debug`; `ctest --preset desktop-fast --build-config Debug`; `powershell -ExecutionPolicy Bypass -File scripts\automation\platform-build.ps1 -Presets android-arm64` | All supported presets consume vcpkg tinyxml2 or document a permanent vendored exception |
 | DEBT-0013 | Open | Modernization | `pp_assets` and `pano_cli inspect-project` recognize only the fixed PPI header, not thumbnail bytes or the project body | Full PPI parsing requires staged extraction of legacy `Canvas` serialization and image/layer payload handling | `ctest --preset desktop-fast --build-config Debug`; `pp_assets_ppi_header_tests` | Full PPI load/save fixtures cover thumbnail, layers, frames, metadata, corrupt payloads, and round-trip compatibility |
+| DEBT-0014 | Open | Modernization | `windows-clangcl-asan` now configures as a headless Ninja/clang-cl preset and uses the release MSVC runtime required by ASan, but local builds still fail because installed clang-cl 18.1.8 is paired with VS 2026-preview STL headers that require Clang 20 or newer | Sanitizer validation should be local and repeatable, but this machine's compiler/header pairing is incompatible | `cmake --fresh --preset windows-clangcl-asan`; `cmake --build --preset windows-clangcl-asan --target pp_foundation` | Install/use Clang 20+ with the VS 2026 STL, or point the preset at a compatible VS 2022 toolchain, then make `platform-build.ps1 -Presets windows-clangcl-asan` pass for the headless matrix |
 
 ## Closed Debt
 

docs/modernization/roadmap.md

@@ -191,7 +191,10 @@ Goal: turn the build into an error-finding system before deep refactors.
 Status: in progress. Initial warning/sanitizer option targets, `vcpkg.json`,
 a validated Windows headless vcpkg preset, `pp_ui_core` support for vcpkg
 tinyxml2 on that preset, and a headless `panopainter_validate_shaders` target
-exist. Dependency migration is not complete until remaining component
+exist. `windows-clangcl-asan` now configures as a headless Ninja/clang-cl ASan
+preset and uses the release MSVC runtime required by clang-cl ASan, but local
+ASan builds are blocked by DEBT-0014 until Clang and the selected MSVC STL are
+compatible. Dependency migration is not complete until remaining component
 dependencies and mobile/Apple triplets are validated.
 
 Implementation tasks:
@@ -545,6 +548,7 @@ ctest --preset desktop-fast-vcpkg --build-config Debug
 cmake --preset android-arm64
 powershell -ExecutionPolicy Bypass -File scripts\automation\platform-build.ps1 -Presets android-arm64
 powershell -ExecutionPolicy Bypass -File scripts\automation\package-smoke.ps1 -Preset windows-msvc-default -Configuration Debug
+cmake --fresh --preset windows-clangcl-asan
 ```
 
 Results:
@@ -585,6 +589,10 @@ Results:
 - `pp_ui_core` built and tested against vcpkg tinyxml2 on
   `windows-msvc-vcpkg-headless` and against the vendored fallback on
   `windows-msvc-default` and `android-arm64`.
+- `windows-clangcl-asan` configures headlessly with clang-cl 18.1.8 and
+  release MSVC runtime selection; build remains blocked and debt-tracked in
+  DEBT-0014 because the selected VS 2026-preview STL requires Clang 20 or
+  newer.
 - `PanoPainter.exe` built through CMake at
   `out/build/windows-msvc-default/Debug/PanoPainter.exe`.
 - PowerShell build/test automation wrappers return JSON summaries and passed