diff --git a/docs/modernization/roadmap.md b/docs/modernization/roadmap.md
index d7779198..045bd86f 100644
--- a/docs/modernization/roadmap.md
+++ b/docs/modernization/roadmap.md
@@ -70,6 +70,9 @@ What is already real:
 - `pp_app_core`
 
 Latest slice:
+- `src/platform_windows/windows_runtime_shell.cpp` no longer keeps a separate
+  retained `AppRuntime*` binding; the touched Windows shell and platform
+  helpers now derive runtime ownership directly from the owned `App`.
 - `src/platform_windows/windows_runtime_shell.cpp` now explicitly owns the
   Windows `App` lifetime through a retained `std::unique_ptr<App>` instead of
   raw `new`/`delete` plus shutdown-side manual cleanup in the lifecycle shell.
@@ -79,6 +82,10 @@ Latest slice:
 - `src/platform_windows/windows_window_shell.cpp` now routes the touched
   key-map and VR-state reads through narrow helpers instead of keeping the
   broader retained-state bundle live across the main window-proc body.
+- `src/platform_legacy/legacy_platform_state.*` no longer exposes the mutable
+  retained GLFW hook bundle; Linux/Web fallback render-context/present/close
+  calls now go through narrow GLFW helper functions instead of an exported hook
+  struct.
 - `scripts/automation/quiet-validate.ps1` is now the bundled checkpoint path
   for Windows build/test plus optional platform and Apple remote validation,
   with one compact JSON summary under `out/logs/quiet-validation`.
diff --git a/docs/modernization/tasks.md b/docs/modernization/tasks.md
index c68808b0..f46bebb5 100644
--- a/docs/modernization/tasks.md
+++ b/docs/modernization/tasks.md
@@ -78,6 +78,9 @@ Completed, blocked, and superseded task history moved to
   the queue is now ordered by code movement instead.
 
 Current slice:
+- `src/platform_windows/windows_runtime_shell.cpp` no longer keeps a separate
+  retained `AppRuntime*`; the touched Windows lifecycle and main-thread task
+  dispatch paths now derive runtime ownership directly from the owned app.
 - `src/platform_windows/windows_runtime_shell.cpp` now owns the Windows `App`
   through a retained `std::unique_ptr<App>`, so startup/early-return/convert
   paths no longer manage raw `new`/`delete` app lifetime manually.
@@ -87,6 +90,9 @@ Current slice:
 - `src/platform_windows/windows_window_shell.cpp` now routes the touched
   key-map synchronization and VR close state through narrow helpers instead of
   carrying the broader retained window bundle live across the window-proc path.
+- `src/platform_legacy/legacy_platform_state.*` no longer exports the mutable
+  retained GLFW hook bundle; Linux/Web fallback render-context, present, and
+  app-close paths now route through narrow GLFW helper functions instead.
 - `scripts/automation/quiet-validate.ps1` now owns the recommended quiet
   checkpoint path and can bundle Windows build/test, Android/platform sweeps,
   and Apple remote compile gates into one compact JSON summary with
diff --git a/src/platform_legacy/legacy_platform_services.cpp b/src/platform_legacy/legacy_platform_services.cpp
index 0e7a67f9..2590d280 100644
--- a/src/platform_legacy/legacy_platform_services.cpp
+++ b/src/platform_legacy/legacy_platform_services.cpp
@@ -177,7 +177,7 @@ public:
 #elif __ANDROID__
         android_async_lock();
 #elif __LINUX__ || __WEB__
-        pp::platform::legacy::active_legacy_glfw_window_hooks().acquire_render_context();
+        pp::platform::legacy::acquire_legacy_glfw_render_context();
 #endif
     }
 
@@ -197,7 +197,7 @@ public:
 #elif __ANDROID__
         android_async_swap();
 #elif __LINUX__ || __WEB__
-        pp::platform::legacy::active_legacy_glfw_window_hooks().present_render_context();
+        pp::platform::legacy::present_legacy_glfw_render_context();
 #endif
     }
 
@@ -508,7 +508,7 @@ public:
 #ifdef __OSX__
         pp::platform::apple::active_legacy_apple_document_platform_services().request_app_close();
 #elif __LINUX__
-        pp::platform::legacy::active_legacy_glfw_window_hooks().request_app_close();
+        pp::platform::legacy::request_legacy_glfw_app_close();
 #endif
     }
 
diff --git a/src/platform_legacy/legacy_platform_state.cpp b/src/platform_legacy/legacy_platform_state.cpp
index 24e35516..dd5945cb 100644
--- a/src/platform_legacy/legacy_platform_state.cpp
+++ b/src/platform_legacy/legacy_platform_state.cpp
@@ -71,24 +71,24 @@ public:
     return state;
 }
 
-[[nodiscard]] RetainedLegacyGlfwWindowHooks& active_legacy_glfw_window_hooks()
-{
-    return active_legacy_glfw_window_state().hooks;
-}
-
 void set_legacy_glfw_window(GLFWwindow* window)
 {
-    auto& retained = active_legacy_glfw_window_state();
-    retained.window = window;
-    retained.hooks.acquire_render_context = [window] {
-        glfwMakeContextCurrent(window);
-    };
-    retained.hooks.present_render_context = [window] {
-        glfwSwapBuffers(window);
-    };
-    retained.hooks.request_app_close = [window] {
-        glfwSetWindowShouldClose(window, GLFW_TRUE);
-    };
+    active_legacy_glfw_window_state().window = window;
+}
+
+void acquire_legacy_glfw_render_context()
+{
+    glfwMakeContextCurrent(active_legacy_glfw_window_state().window);
+}
+
+void present_legacy_glfw_render_context()
+{
+    glfwSwapBuffers(active_legacy_glfw_window_state().window);
+}
+
+void request_legacy_glfw_app_close()
+{
+    glfwSetWindowShouldClose(active_legacy_glfw_window_state().window, GLFW_TRUE);
 }
 #endif
 
diff --git a/src/platform_legacy/legacy_platform_state.h b/src/platform_legacy/legacy_platform_state.h
index 916e3bdb..1437b427 100644
--- a/src/platform_legacy/legacy_platform_state.h
+++ b/src/platform_legacy/legacy_platform_state.h
@@ -9,20 +9,15 @@ struct GLFWwindow;
 namespace pp::platform::legacy {
 
 #if defined(__LINUX__) || defined(__WEB__)
-struct RetainedLegacyGlfwWindowHooks final {
-    std::function<void()> acquire_render_context;
-    std::function<void()> present_render_context;
-    std::function<void()> request_app_close;
-};
-
 struct RetainedLegacyGlfwWindowState final {
     GLFWwindow* window = nullptr;
-    RetainedLegacyGlfwWindowHooks hooks;
 };
 
 [[nodiscard]] RetainedLegacyGlfwWindowState& active_legacy_glfw_window_state();
-[[nodiscard]] RetainedLegacyGlfwWindowHooks& active_legacy_glfw_window_hooks();
 void set_legacy_glfw_window(GLFWwindow* window);
+void acquire_legacy_glfw_render_context();
+void present_legacy_glfw_render_context();
+void request_legacy_glfw_app_close();
 #endif
 
 [[nodiscard]] pp::platform::WebPlatformServices& active_legacy_web_platform_services();
diff --git a/src/platform_windows/windows_lifecycle_shell.cpp b/src/platform_windows/windows_lifecycle_shell.cpp
index 64717543..bf274053 100644
--- a/src/platform_windows/windows_lifecycle_shell.cpp
+++ b/src/platform_windows/windows_lifecycle_shell.cpp
@@ -47,11 +47,10 @@ void request_window_close(HWND hWnd)
 void handle_window_close_message(VrShellState& vr)
 {
     auto* app = bound_app();
-    auto* runtime = bound_runtime();
     mark_lifecycle_stopped();
     request_stop_and_join_vr_thread(vr);
-    runtime->ui_thread_stop();
-    runtime->render_thread_stop();
+    app->runtime().ui_thread_stop();
+    app->runtime().render_thread_stop();
     app->terminate();
     release_bound_app();
     PostQuitMessage(0);
diff --git a/src/platform_windows/windows_platform_services.cpp b/src/platform_windows/windows_platform_services.cpp
index b7468ed4..73f51761 100644
--- a/src/platform_windows/windows_platform_services.cpp
+++ b/src/platform_windows/windows_platform_services.cpp
@@ -186,9 +186,9 @@ void swap_async_render_context()
 
 void enqueue_main_thread_task(std::packaged_task<void()> task)
 {
-    if (auto* runtime = bound_runtime())
+    if (auto* app = bound_app())
     {
-        runtime->main_thread_task(std::move(task));
+        app->runtime().main_thread_task(std::move(task));
         return;
     }
 
@@ -200,9 +200,9 @@ void enqueue_main_thread_task(std::packaged_task<void()> task)
 
 void drain_main_thread_tasks()
 {
-    if (auto* runtime = bound_runtime())
+    if (auto* app = bound_app())
     {
-        runtime->drain_main_thread_tasks();
+        app->runtime().drain_main_thread_tasks();
         return;
     }
 }
diff --git a/src/platform_windows/windows_runtime_shell.cpp b/src/platform_windows/windows_runtime_shell.cpp
index 630732dc..e6d10c8e 100644
--- a/src/platform_windows/windows_runtime_shell.cpp
+++ b/src/platform_windows/windows_runtime_shell.cpp
@@ -3,7 +3,6 @@
 #include "platform_windows/windows_runtime_shell.h"
 
 #include "app.h"
-#include "app_runtime.h"
 #include "log.h"
 #include "platform_windows/windows_bootstrap_helpers.h"
 #include "platform_windows/windows_lifecycle_shell.h"
@@ -20,7 +19,6 @@ namespace {
 struct RetainedWindowsRuntimeState final {
     std::unique_ptr<App> owned_app;
     App* app = nullptr;
-    AppRuntime* runtime = nullptr;
     WacomTablet* tablet = nullptr;
 };
 
@@ -42,10 +40,9 @@ void register_touch_window(HWND hWnd)
 void initialize_runtime_threads()
 {
     auto* app = bound_app();
-    auto* runtime = bound_runtime();
     mark_lifecycle_running();
-    runtime->render_thread_start(*app);
-    runtime->ui_thread_start(*app);
+    app->runtime().render_thread_start(*app);
+    app->runtime().ui_thread_start(*app);
 }
 
 void install_debug_gl_callbacks()
@@ -136,21 +133,10 @@ App* bound_app() noexcept
 void release_bound_app() noexcept
 {
     auto& state = retained_runtime_state();
-    bind_runtime(nullptr);
     bind_app(nullptr);
     state.owned_app.reset();
 }
 
-void bind_runtime(AppRuntime* runtime) noexcept
-{
-    retained_runtime_state().runtime = runtime;
-}
-
-AppRuntime* bound_runtime() noexcept
-{
-    return retained_runtime_state().runtime;
-}
-
 void bind_wacom_tablet(WacomTablet* tablet) noexcept
 {
     retained_runtime_state().tablet = tablet;
@@ -190,7 +176,6 @@ int run_main_application(int argc, char** argv)
     runtime_state.owned_app = std::make_unique<App>();
     auto* app = runtime_state.owned_app.get();
     bind_app(app);
-    bind_runtime(&app->runtime());
     bind_wacom_tablet(&WacomTablet::I);
     app->set_platform_services(&pp::platform::windows::platform_services());
     app->initLog();
diff --git a/src/platform_windows/windows_runtime_shell.h b/src/platform_windows/windows_runtime_shell.h
index e2e5c357..a0a99928 100644
--- a/src/platform_windows/windows_runtime_shell.h
+++ b/src/platform_windows/windows_runtime_shell.h
@@ -4,7 +4,6 @@
 #include "platform_windows/windows_splash.h"
 
 class App;
-class AppRuntime;
 class WacomTablet;
 
 namespace pp::platform::windows {
@@ -14,8 +13,6 @@ void run_main_window_runtime(const MainWindowStartupState& startup, bool start_i
 void bind_app(App* app) noexcept;
 [[nodiscard]] App* bound_app() noexcept;
 void release_bound_app() noexcept;
-void bind_runtime(AppRuntime* runtime) noexcept;
-[[nodiscard]] AppRuntime* bound_runtime() noexcept;
 void bind_wacom_tablet(WacomTablet* tablet) noexcept;
 [[nodiscard]] WacomTablet* bound_wacom_tablet() noexcept;
 [[nodiscard]] HWND main_window_handle() noexcept;