diff --git a/docs/modernization/build-inventory.md b/docs/modernization/build-inventory.md
index 5b6d6b8..90e8103 100644
--- a/docs/modernization/build-inventory.md
+++ b/docs/modernization/build-inventory.md
@@ -1,7 +1,7 @@
 # Build And Platform Inventory
 
 Status: live
-Last updated: 2026-06-03
+Last updated: 2026-06-04
 
 This inventory records the known build surfaces during the CMake migration.
 Keep it updated as platform paths move to shared CMake targets.
@@ -542,8 +542,9 @@ Known local toolchain state:
   app/window close, UI-thread lifecycle hooks, render-context lifecycle hooks,
   render-target binding hooks, render platform hint hooks, render-capture frame
   hooks, render debug callback hooks, per-frame platform hooks, picker
-  callbacks, and recording cleanup, live asset/layout reload policy, diagnostic
-  stacktrace/crash hooks, prepared-file save/download handoff;
+  callbacks, recording cleanup, exported-image publishing, persistent storage
+  flushing, live asset/layout reload policy, diagnostic stacktrace/crash hooks,
+  prepared-file save/download handoff;
   Windows
   live app execution now uses injected
   `WindowsPlatformServices` from
diff --git a/docs/modernization/debt.md b/docs/modernization/debt.md
index 0293911..8def995 100644
--- a/docs/modernization/debt.md
+++ b/docs/modernization/debt.md
@@ -67,6 +67,7 @@ agent or engineer to remove them without reconstructing context from chat.
 | DEBT-0047 | Open | Modernization | PPBR brush package export request validation and execution dispatch now consume pure `pp_app_core` through `App::dialog_ppbr_export`, `pano_cli plan-brush-package-export`, `BrushPackageExportServices`, and `src/legacy_brush_package_export_services.*`; PPBR header/path planning now consumes `pp_assets::brush_package`, but the bridge still reads `NodeDialogExportPPBR`, carries the legacy `Image` header object outside the pure request, converts to `NodePanelBrushPreset::PPBRInfo`, calls `NodePanelBrushPreset::export_ppbr`, owns desktop worker-thread dispatch, dialog destruction, mobile/Web completion, and success-message behavior directly | Preserve current PPBR export behavior while brush assets, PPBR serialization, picker completion, and UI lifetime move toward asset/storage/UI/platform services | `pp_assets_brush_package_tests`; `pp_app_core_brush_package_export_tests`; `pano_cli plan-brush-package-export --path D:/Paint/clouds.ppbr --author Artist --dest-path D:/Paint/BrushPreviews --export-data --header-image`; `pano_cli plan-brush-package-export`; `pano_cli plan-brush-package-export --path clouds`; `pano_cli plan-brush-package-export --path D:/Paint/clouds.ppbr --dest-path D:/Paint/BrushPreviews --no-export-data`; `ctest --preset desktop-fast --build-config Debug`; `cmake --build --preset windows-msvc-default --config Debug --target PanoPainter` | PPBR metadata collection, header-image ownership, serialization, picker-selected path execution, desktop threading, dialog lifetime, and success UI are owned by injected brush asset/storage/UI/platform services with `App::dialog_ppbr_export` acting only as a UI adapter |
 | DEBT-0048 | Open | Modernization | ABR/PPBR brush package import execution now consumes pure `pp_app_core` through document-open confirmation callbacks, `pano_cli plan-brush-package-import`, `BrushPackageImportServices`, and `src/legacy_brush_package_import_services.*`; imported brush tip/pattern target paths now consume `pp_assets::brush_package`, but the bridge still launches detached legacy `NodePanelBrushPreset::import_abr`/`import_ppbr` worker threads and depends on the legacy preset panel as the importer/storage owner | Preserve current brush import behavior while brush package parsing, preset storage, progress/error reporting, and UI refresh move toward asset/paint/UI services | `pp_assets_brush_package_tests`; `pp_app_core_brush_package_import_tests`; `pano_cli plan-brush-package-import --kind ppbr --path D:/Paint/Brushes/clouds.ppbr`; `pano_cli plan-brush-package-import --kind abr --path D:/Paint/Brushes/clouds.abr`; `pano_cli plan-brush-package-import --kind ppbr`; `ctest --preset desktop-fast --build-config Debug`; `cmake --build --preset windows-msvc-default --config Debug --target PanoPainter` | ABR/PPBR parsing, preset creation/storage, import threading/progress, duplicate asset policy, and UI refresh are owned by injected brush asset/paint/UI services with document-open callbacks only confirming user intent |
 | DEBT-0049 | Open | Modernization | `pp_assets::validate_ppbr_header` intentionally preserves the legacy PPBR version check from `NodePanelBrushPreset::import_ppbr`, which accepts files when either major is `0` or minor is `1` instead of requiring exactly version `0.1` | Avoid rejecting existing brush packages before compatibility fixtures prove the stricter rule is safe | `pp_assets_brush_package_tests`; `pano_cli plan-brush-package-export --path D:/Paint/clouds.ppbr`; `ctest --preset desktop-fast --build-config Debug`; `cmake --build --preset windows-msvc-default --config Debug --target PanoPainter` | Add PPBR compatibility fixtures for accepted/rejected historical package versions, then require canonical `0.1` or an explicit supported-version matrix and update live import accordingly |
+| DEBT-0050 | Open | Modernization | iOS exported-image photo-library publishing and WebGL persistent-storage flushing now dispatch through `PlatformServices`, but non-Windows execution still lives in `src/platform_legacy/legacy_platform_services.*` and forwards to retained `save_image_library`/`webgl_sync` bridges | Preserve current iOS/Web export and save behavior while the Apple/Web platform shells are extracted incrementally | `pp_platform_api_tests`; `ctest --preset desktop-fast --build-config Debug`; platform package smoke once Apple/Web root builds exist | Exported-image publishing and persistent-storage flushing are owned by injected Apple/Web `pp_platform_*` services with no legacy adapter branch |
 
 ## Closed Debt
 
diff --git a/docs/modernization/roadmap.md b/docs/modernization/roadmap.md
index a84ebc7..e8df039 100644
--- a/docs/modernization/roadmap.md
+++ b/docs/modernization/roadmap.md
@@ -1,7 +1,7 @@
 # PanoPainter Modernization Roadmap
 
 Status: live
-Last updated: 2026-06-03
+Last updated: 2026-06-04
 
 This is the living roadmap for modernizing PanoPainter into independently
 testable C++23 components while retaining all existing functionality. Keep this
@@ -639,6 +639,10 @@ is preserved while their platform shell implementations are extracted.
 Prepared-file save/download handoff is now also part of the service contract,
 so iOS/Web export completion routes through `PlatformServices` after the app
 writes the temporary/exported payload.
+Canvas image export publishing and explicit persistent-storage flushes now
+dispatch through `PlatformServices` too, preserving iOS photo-library export
+publication and WebGL filesystem sync behavior in the legacy adapter while
+removing those direct platform calls from `Canvas` and brush preset storage.
 `App::show_cursor`, `App::hide_cursor`, `App::showKeyboard`, and
 `App::hideKeyboard` now dispatch through the active service without local
 platform guards; unsupported platforms rely on their service no-op behavior.
@@ -1679,7 +1683,8 @@ Results:
   app/window close dispatch, UI-thread lifecycle dispatch, render-context
   lifecycle dispatch, render-target binding dispatch, render platform hint
   dispatch, render debug callback dispatch, render-capture frame hook dispatch,
-  recording cleanup dispatch, live asset/layout reload policy dispatch,
+  recording cleanup dispatch, exported-image publish dispatch, persistent
+  storage flush dispatch, live asset/layout reload policy dispatch,
   diagnostic hook dispatch, per-frame platform hook dispatch, picker callback
   dispatch, and prepared-file save/download callback dispatch. The live Windows
   app now
diff --git a/src/app.h b/src/app.h
index 6367493..bef9f39 100644
--- a/src/app.h
+++ b/src/app.h
@@ -204,6 +204,8 @@ public:
     void end_render_capture_frame();
     [[nodiscard]] bool platform_deletes_recorded_files_on_clear();
     void clear_platform_recorded_files(std::string path);
+    void publish_exported_image(std::string path);
+    void flush_platform_storage();
     [[nodiscard]] bool platform_enables_live_asset_reloading();
     void update_platform_frame(float delta_time_seconds);
     void report_rendered_frames(int frames);
diff --git a/src/app_dialogs.cpp b/src/app_dialogs.cpp
index 87a2fe2..c3839ef 100644
--- a/src/app_dialogs.cpp
+++ b/src/app_dialogs.cpp
@@ -31,7 +31,6 @@
 #include "oculus_vr.h"
 #elif __WEB__
 void webgl_pick_file(std::function<void(std::string)> callback);
-void webgl_sync();
 #endif
 
 namespace {
diff --git a/src/app_events.cpp b/src/app_events.cpp
index 74727fb..205c770 100644
--- a/src/app_events.cpp
+++ b/src/app_events.cpp
@@ -277,6 +277,16 @@ void App::clear_platform_recorded_files(std::string path)
     active_platform_services().clear_recorded_files(path);
 }
 
+void App::publish_exported_image(std::string path)
+{
+    active_platform_services().publish_exported_image(path);
+}
+
+void App::flush_platform_storage()
+{
+    active_platform_services().flush_persistent_storage();
+}
+
 bool App::platform_enables_live_asset_reloading()
 {
     return active_platform_services().enables_live_asset_reloading();
diff --git a/src/canvas.cpp b/src/canvas.cpp
index 091fec9..02b6656 100644
--- a/src/canvas.cpp
+++ b/src/canvas.cpp
@@ -13,9 +13,6 @@
 
 #ifdef __APPLE__
 #include <Foundation/Foundation.h>
-#import "objc_utils.h"
-#elif __WEB__
-void webgl_sync();
 #endif
 
 namespace {
@@ -2021,9 +2018,7 @@ void Canvas::export_equirectangular_thread(std::string file_path)
         data.save_png(file_path);
     }
 
-#ifdef __IOS__
-    save_image_library(file_path);
-#endif
+    App::I->publish_exported_image(file_path);
 }
 
 void Canvas::inject_xmp(std::string jpg_path)
@@ -2305,9 +2300,7 @@ void Canvas::export_cube_faces_thread(std::string file_name)
         face.save_png(path);
         pb->increment();
 
-#ifdef __IOS__
-        save_image_library(path);
-#endif
+        App::I->publish_exported_image(path);
 #ifdef __OBJC__
         [files addObject : [NSString stringWithUTF8String:path.c_str()] ];
 #endif
@@ -2575,9 +2568,7 @@ bool Canvas::project_save_thread(std::string file_path, bool show_progress)
             if (!sw.save(lapse_path))
                 LOG("cannot save timelase to %s", lapse_path.c_str());
         }
-#if __WEB__
-        webgl_sync();
-#endif
+        App::I->flush_platform_storage();
     }
 
     if (show_progress)
diff --git a/src/node_panel_brush.cpp b/src/node_panel_brush.cpp
index 9d10bac..9fabb57 100644
--- a/src/node_panel_brush.cpp
+++ b/src/node_panel_brush.cpp
@@ -9,8 +9,6 @@
 
 #ifdef __APPLE__
 #include <Foundation/Foundation.h>
-#elif __WEB__
-void webgl_sync();
 #endif
 
 #include "canvas.h"
@@ -244,9 +242,7 @@ bool NodePanelBrush::save()
         }
         f.write((char*)sw.m_data.data(), sw.m_data.size());
         f.close();
-#if __WEB__
-        webgl_sync();
-#endif
+        App::I->flush_platform_storage();
         return true;
     }
     return false;
diff --git a/src/platform_api/platform_services.h b/src/platform_api/platform_services.h
index a0ded6a..afb7fe5 100644
--- a/src/platform_api/platform_services.h
+++ b/src/platform_api/platform_services.h
@@ -41,6 +41,8 @@ public:
     virtual void end_render_capture_frame() = 0;
     [[nodiscard]] virtual bool deletes_recorded_files_on_clear() = 0;
     virtual void clear_recorded_files(std::string_view recording_path) = 0;
+    virtual void publish_exported_image(std::string_view path) = 0;
+    virtual void flush_persistent_storage() = 0;
     [[nodiscard]] virtual bool enables_live_asset_reloading() = 0;
     virtual void update_platform_frame(float delta_time_seconds) = 0;
     virtual void report_rendered_frames(int frames) = 0;
diff --git a/src/platform_legacy/legacy_platform_services.cpp b/src/platform_legacy/legacy_platform_services.cpp
index 9abb84e..09afc9d 100644
--- a/src/platform_legacy/legacy_platform_services.cpp
+++ b/src/platform_legacy/legacy_platform_services.cpp
@@ -18,6 +18,9 @@ std::string android_get_clipboard();
 bool android_set_clipboard(const std::string& s);
 #elif __APPLE__
 void delete_all_files_in_path(const std::string& source_path);
+#ifdef __IOS__
+void save_image_library(const std::string& path);
+#endif
 #elif __LINUX__
 #include <tinyfiledialogs.h>
 std::string linux_home_path();
@@ -279,6 +282,22 @@ public:
 #endif
     }
 
+    void publish_exported_image(std::string_view path) override
+    {
+#ifdef __IOS__
+        save_image_library(std::string(path));
+#else
+        (void)path;
+#endif
+    }
+
+    void flush_persistent_storage() override
+    {
+#ifdef __WEB__
+        webgl_sync();
+#endif
+    }
+
     [[nodiscard]] bool enables_live_asset_reloading() override
     {
 #if defined(__OSX__)
diff --git a/src/platform_windows/windows_platform_services.cpp b/src/platform_windows/windows_platform_services.cpp
index 112e4eb..415ef64 100644
--- a/src/platform_windows/windows_platform_services.cpp
+++ b/src/platform_windows/windows_platform_services.cpp
@@ -369,6 +369,15 @@ public:
         (void)recording_path;
     }
 
+    void publish_exported_image(std::string_view path) override
+    {
+        (void)path;
+    }
+
+    void flush_persistent_storage() override
+    {
+    }
+
     [[nodiscard]] bool enables_live_asset_reloading() override
     {
         return true;
diff --git a/tests/platform_api/platform_services_tests.cpp b/tests/platform_api/platform_services_tests.cpp
index 3c69680..9d35ff1 100644
--- a/tests/platform_api/platform_services_tests.cpp
+++ b/tests/platform_api/platform_services_tests.cpp
@@ -123,6 +123,17 @@ public:
         cleared_recording_path.assign(recording_path);
     }
 
+    void publish_exported_image(std::string_view path) override
+    {
+        ++exported_image_publishes;
+        exported_image_path.assign(path);
+    }
+
+    void flush_persistent_storage() override
+    {
+        ++persistent_storage_flushes;
+    }
+
     [[nodiscard]] bool enables_live_asset_reloading() override
     {
         ++live_asset_reload_policy_checks;
@@ -215,6 +226,8 @@ public:
     int crash_tests = 0;
     int recording_delete_policy_checks = 0;
     int recording_clears = 0;
+    int exported_image_publishes = 0;
+    int persistent_storage_flushes = 0;
     int live_asset_reload_policy_checks = 0;
     int platform_frame_updates = 0;
     int frame_reports = 0;
@@ -238,6 +251,7 @@ public:
     std::string prepared_file_path;
     std::string prepared_file_name;
     std::string cleared_recording_path;
+    std::string exported_image_path;
     std::string picker_path = "D:/Paint/import.png";
     std::string save_path = "D:/Paint/export.ppi";
     std::string directory_path = "D:/Paint";
@@ -377,6 +391,19 @@ void platform_services_dispatch_recording_cleanup(pp::tests::Harness& harness)
     PP_EXPECT(harness, fake.cleared_recording_path == "D:/Paint/frames");
 }
 
+void platform_services_dispatch_exported_image_and_storage_flush(pp::tests::Harness& harness)
+{
+    FakePlatformServices fake("unused");
+    pp::platform::PlatformServices& services = fake;
+
+    services.publish_exported_image("D:/Paint/export.png");
+    services.flush_persistent_storage();
+
+    PP_EXPECT(harness, fake.exported_image_publishes == 1);
+    PP_EXPECT(harness, fake.exported_image_path == "D:/Paint/export.png");
+    PP_EXPECT(harness, fake.persistent_storage_flushes == 1);
+}
+
 void platform_services_dispatch_live_asset_reload_policy(pp::tests::Harness& harness)
 {
     FakePlatformServices fake("unused");
@@ -481,6 +508,7 @@ int main()
     harness.run("platform services dispatch render context lifecycle", platform_services_dispatch_render_context_lifecycle);
     harness.run("platform services dispatch render capture hooks", platform_services_dispatch_render_capture_hooks);
     harness.run("platform services dispatch recording cleanup", platform_services_dispatch_recording_cleanup);
+    harness.run("platform services dispatch exported image and storage flush", platform_services_dispatch_exported_image_and_storage_flush);
     harness.run("platform services dispatch live asset reload policy", platform_services_dispatch_live_asset_reload_policy);
     harness.run("platform services dispatch frame hooks", platform_services_dispatch_frame_hooks);
     harness.run("platform services dispatch file actions", platform_services_dispatch_file_actions);