Own Linux platform services and narrow legacy fallback

docs/modernization/roadmap.md

@@ -70,6 +70,19 @@ What is already real:
 - `pp_app_core`
 
 Latest slice:
+- `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
+  `platform_legacy`.
+- `linux/src/main.cpp` now binds that owned Linux `PlatformServices` instance
+  into `App` directly at the Linux entrypoint.
+- The touched Linux storage-path setup, GLFW render-context acquire/present,
+  app-close dispatch, default render-target binding, desktop file picking, and
+  FPS reporting now route through `src/platform_linux/linux_platform_services.*`
+  instead of the cross-platform fallback adapter.
+- `src/platform_legacy/legacy_platform_services.*` no longer carries the
+  touched Linux method branches, so the retained fallback adapter is narrower
+  again and now focused on the Web path plus generic fallback policy.
 - `src/platform_android/android_platform_services.*` now owns the concrete
   Android `PlatformServices` implementation and `create_platform_services()`
   instead of leaving the live Android execution surface inside
@@ -82,8 +95,7 @@ Latest slice:
   cross-platform fallback adapter.
 - `src/platform_legacy/legacy_platform_services.*` no longer carries the
   Android bridge/configuration surface or the touched Android method branches,
-  so the retained fallback adapter is narrower again and now focused on the
-  Linux/Web path plus generic fallback policy.
+  so the retained fallback adapter was narrowed again before the Linux cut.
 - `src/platform_apple/apple_platform_services.*` now owns the concrete Apple
   `PlatformServices` implementation plus the `create_apple_platform_services()`
   factory instead of leaving the live Apple execution surface inside