Own Web platform services and remove legacy web state

docs/modernization/roadmap.md

@@ -70,6 +70,20 @@ What is already real:
 - `pp_app_core`
 
 Latest slice:
+- `src/platform_web/web_platform_services.*` now owns the concrete Web
+  `PlatformServices` implementation and `webgl/src/main.cpp` now binds that
+  owned service directly at the WebGL entrypoint.
+- The touched Web storage-path setup, GLFW render-context acquire/present,
+  app-close dispatch, prepared-file save handoff, persistent-storage flush,
+  default render-target binding, and picker execution now route through
+  `src/platform_web/web_platform_services.*` instead of the cross-platform
+  fallback adapter.
+- `src/platform_legacy/legacy_platform_services.*` no longer carries the
+  touched Web method branches or the retained `WebPlatformServices*`
+  dependency, and `src/platform_legacy/legacy_platform_state.*` is gone.
+- `pp_platform_web` now exists as the concrete Web target in root CMake and is
+  linked into `pp_platform_api_tests`, while `webgl/CMakeLists.txt` also
+  compiles the concrete Web service directly for the retained WebGL app build.
 - `src/platform_linux/linux_platform_services.*` now owns the concrete Linux
   `PlatformServices` implementation and `create_platform_services(...)`
   instead of leaving the live Linux execution surface inside
@@ -112,15 +126,9 @@ Latest slice:
   document-service provider/configuration surface or the touched Apple method
   branches, so the retained fallback adapter is narrower and now focused on the
   Android/Linux/Web path.
-- `src/platform_legacy/legacy_platform_services.*` now takes an explicit
-  `WebPlatformServices*` dependency through `create_platform_services(...)`
-  instead of routing WebGL publish/flush/default-canvas/save-prepared-file
-  behavior through retained `try_*legacy_web*` fallback helpers.
-- `webgl/src/main.cpp` now creates the owned Web service first and threads it
-  directly into its owned legacy `PlatformServices` instance.
-- `src/platform_legacy/legacy_platform_state.*` is down to the retained Web
-  service factory only; the old `active_legacy_web_platform_services()` and
-  `try_*legacy_web*` dispatch layer are gone.
+- The previous Web narrowing step had already moved WebGL
+  publish/flush/default-canvas/save-prepared-file behavior off the old
+  `try_*legacy_web*` fallback path before this concrete Web service cut.
 - `src/platform_legacy/legacy_platform_services.*` no longer exposes the dead
   `pp::platform::legacy::platform_services()` singleton accessor.
 - Linux, WebGL, and Android were already on owned