Own Web platform services and remove legacy web state

docs/modernization/build-inventory.md

@@ -18,7 +18,7 @@ Keep it updated as platform paths move to shared CMake targets.
 | Android Quest | `android/quest/build.gradle`, `android/quest/CMakeLists.txt` | OVR SDK imported libraries; CMake 3.10/C++23 baseline and current Yoga source list configure with the shared Android package compatibility helper |
 | Android Focus/Wave | `android/focus/build.gradle`, `android/focus/CMakeLists.txt` | Wave SDK imported libraries; CMake 3.10/C++23 baseline and current Yoga source list configure with the shared Android package compatibility helper |
 | Linux | `linux/CMakeLists.txt` | Retained app target now uses CMake 3.10 and target-level C++23 while package/root target migration remains open; the modern root CMake path now splits Linux helper code into `pp_platform_linux` instead of leaving it inside `pp_platform_api` |
-| WebGL/Emscripten | `webgl/CMakeLists.txt` | Retained WebGL app target now uses CMake 3.10 and target-level C++23 with retained WebGL2/Emscripten link flags |
+| WebGL/Emscripten | `webgl/CMakeLists.txt` | Retained WebGL app target now uses CMake 3.10 and target-level C++23 with retained WebGL2/Emscripten link flags, and the modern root CMake path now also exposes concrete Web helper code through `pp_platform_web` instead of leaving the live Web execution inside `platform_legacy` |
 
 ## Existing Version Generation
 

docs/modernization/debt.md

@@ -18,6 +18,14 @@ agent or engineer to remove them without reconstructing context from chat.
 
 ## Reductions
 
+- 2026-06-17: `DEBT-0016`/`DEBT-0017`/`DEBT-0050`/`DEBT-0051`/`DEBT-0053`/
+  `DEBT-0057` were narrowed again. `src/platform_web/web_platform_services.*`
+  now owns the concrete Web `PlatformServices` implementation and
+  `webgl/src/main.cpp` now binds that owned service directly, so
+  `src/platform_legacy/legacy_platform_services.*` no longer carries the
+  touched Web render-context, app-close, picker, storage-path,
+  persistent-storage, default-canvas, prepared-file, or default-render-target
+  branches, and `src/platform_legacy/legacy_platform_state.*` is gone.
 - 2026-06-17: `DEBT-0016`/`DEBT-0017`/`DEBT-0051` were narrowed again.
   `src/platform_linux/linux_platform_services.*` now owns the concrete Linux
   `PlatformServices` implementation and `linux/src/main.cpp` now binds that

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

docs/modernization/tasks.md

@@ -53,8 +53,9 @@ Completed, blocked, and superseded task history moved to
     `PlatformServices` surface now binds directly from those Apple-owned files,
     and Android now also binds directly from
     `src/platform_android/android_platform_services.*`, and Linux now also
-    binds directly from `src/platform_linux/linux_platform_services.*`, but the
-    broader non-Windows fallback adapter still exists for Web plus generic
+    binds directly from `src/platform_linux/linux_platform_services.*`, and Web
+    now also binds directly from `src/platform_web/web_platform_services.*`,
+    but the broader non-Windows fallback adapter still exists as generic
     fallback policy
   - `platform_legacy` is still part of the live app shell
 - The app runtime boundary is not finished:
@@ -83,6 +84,20 @@ Completed, blocked, and superseded task history moved to
   the queue is now ordered by code movement instead.
 
 Current 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 in `platform_legacy`.
@@ -124,15 +139,9 @@ Current 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