Bind non-Windows platform services explicitly

docs/modernization/roadmap.md

@@ -70,6 +70,13 @@ What is already real:
 - `pp_app_core`
 
 Latest slice:
+- `src/app_events.cpp` no longer silently falls back to
+  `pp::platform::legacy::platform_services()` when `App` has no bound platform
+  services; the live app path now expects explicit platform-service ownership.
+- `linux/src/main.cpp`, `webgl/src/main.cpp`, and `android/src/cpp/main.cpp`
+  now bind `pp::platform::legacy::platform_services()` explicitly at app
+  creation instead of relying on the hidden fallback in `App` event/platform
+  dispatch.
 - `src/platform_windows/windows_runtime_shell.cpp` now owns the Windows tablet
   object directly; the composition edge no longer binds `&WacomTablet::I` into
   the Windows runtime path.