diff --git a/.github/workflows/native-runtime-packages.yml b/.github/workflows/native-runtime-packages.yml
index 797da280a..e6dcca2ca 100644
--- a/.github/workflows/native-runtime-packages.yml
+++ b/.github/workflows/native-runtime-packages.yml
@@ -333,6 +333,15 @@ jobs:
           --upstream-v8 \
           --partition-alloc \
           --output "$GITHUB_WORKSPACE/artifacts/nuget-packages"
+    - name: Upload exact macOS native symbols
+      if: matrix.rid == 'osx-arm64'
+      uses: actions/upload-artifact@v4
+      with:
+        name: native-symbols-${{ matrix.rid }}-${{ needs.metadata.outputs.package-version }}
+        path: artifacts/native-engine-runtime-build/**/*.dSYM/**
+        if-no-files-found: error
+        compression-level: 9
+        retention-days: 3
     - name: Build, pack, and test Linux runtime
       if: matrix.rid == 'linux-x64'
       shell: bash
diff --git a/experiments/WebScene.NativeEngine.Probe/native/webscene_v8_runtime_lifecycle.inc b/experiments/WebScene.NativeEngine.Probe/native/webscene_v8_runtime_lifecycle.inc
index 18a27a22f..58582475a 100644
--- a/experiments/WebScene.NativeEngine.Probe/native/webscene_v8_runtime_lifecycle.inc
+++ b/experiments/WebScene.NativeEngine.Probe/native/webscene_v8_runtime_lifecycle.inc
@@ -149,6 +149,12 @@
         pending_programmatic_scroll_events.clear();
         pending_interop_promises.clear();
         pending_callback_promises.clear();
+        // Native host and file completions can still be pending when a window
+        // closes. Their persistent context/resolver handles must be released
+        // while the isolate is alive; member destruction happens after this
+        // body and therefore after isolate disposal below.
+        host_promise_targets.clear();
+        file_targets.clear();
         pending_fetches.clear();
         interop_handles.clear();
         pending_promise_rejections.clear();
diff --git a/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_browser_dom_tests.inc b/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_browser_dom_tests.inc
index aa38c37a7..979d953d8 100644
--- a/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_browser_dom_tests.inc
+++ b/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_browser_dom_tests.inc
@@ -3180,6 +3180,127 @@ void test_native_clipboard_shortcut_events(webscene_engine*)
     webscene_engine_destroy(engine);
 }
 
+void test_native_legacy_clipboard_completion_stress(webscene_engine*)
+{
+    auto* engine = webscene_engine_create(0);
+    require(engine != nullptr,
+        "legacy clipboard completion stress engine creation failed");
+    execute_and_wait(engine, R"JS(
+        document.body.innerHTML = '<textarea id="legacy-copy-stress"></textarea>';
+        const editor = document.getElementById('legacy-copy-stress');
+        globalThis.__legacyCopyStressEvents = 0;
+        globalThis.__legacyCopyStressResults = [];
+        editor.addEventListener('keydown', event => {
+          if (event.metaKey && event.key.toLowerCase() === 'c') {
+            event.preventDefault();
+            __legacyCopyStressResults.push(document.execCommand('copy'));
+          }
+        });
+        editor.addEventListener('copy', event => {
+          event.clipboardData.setData('text/plain', 'legacy stress');
+          event.preventDefault();
+          ++__legacyCopyStressEvents;
+        });
+        editor.focus();
+    )JS", "native-legacy-clipboard-stress-setup.js");
+
+    constexpr unsigned operation_count = 10000U;
+    constexpr unsigned batch_size = 16U;
+    constexpr auto modifier = WEBSCENE_INPUT_MODIFIER_META;
+    uint64_t sequence = 20000U;
+    const auto started = std::chrono::steady_clock::now();
+    for (unsigned offset = 0; offset < operation_count; offset += batch_size) {
+        for (unsigned index = 0; index < batch_size; ++index) {
+            keyboard_input(
+                engine, WEBSCENE_INPUT_KEY_DOWN, 'C', sequence++, modifier);
+        }
+        webscene_engine_metrics metrics{};
+        webscene_engine_get_metrics(engine, &metrics);
+        wait_for_consumed_inputs(
+            engine, metrics.enqueued_inputs,
+            "legacy clipboard stress input was not consumed");
+        for (unsigned index = 0; index < batch_size; ++index) {
+            const auto request = take_typed_host_request(engine);
+            require(
+                request.kind == WEBSCENE_HOST_REQUEST_CLIPBOARD_WRITE_V1
+                    && request.flags
+                        == WEBSCENE_HOST_REQUEST_CLIPBOARD_REPLACE_V1
+                    && request.content_type == "text/plain"
+                    && std::string(request.bytes.begin(), request.bytes.end())
+                        == "legacy stress",
+                "legacy clipboard stress request changed");
+            require(webscene_engine_complete_host_request_v1(
+                        engine, request.id, 0U, "text/plain",
+                        nullptr, 0U, nullptr) != 0,
+                "legacy clipboard stress completion was rejected");
+        }
+        const auto expected = offset + batch_size;
+        require(evaluate(
+                    engine,
+                    "__legacyCopyStressEvents === " + std::to_string(expected)
+                        + " && __legacyCopyStressResults.length === "
+                        + std::to_string(expected)
+                        + " && __legacyCopyStressResults.every(Boolean)",
+                    "native-legacy-clipboard-stress-barrier.js") == "true",
+            "legacy clipboard stress did not drain completions in order");
+    }
+    require(!take_typed_host_request(engine),
+        "legacy clipboard stress retained a host request");
+    const auto elapsed = std::chrono::duration<double>(
+        std::chrono::steady_clock::now() - started).count();
+    require(elapsed < 15.0,
+        "10,000 legacy clipboard completions exceeded fifteen seconds");
+    std::cout << "Legacy clipboard completion gate: operations="
+              << operation_count << " pendingHighWater=" << batch_size
+              << " elapsed=" << elapsed << "s\n";
+    // Reproduce the packaged close boundary: the worker destroys all resolved
+    // promise/microtask state immediately after the last public-ABI barrier.
+    webscene_engine_destroy(engine);
+}
+
+void test_native_pending_legacy_clipboard_shutdown(webscene_engine*)
+{
+    auto* engine = webscene_engine_create(0);
+    require(engine != nullptr,
+        "pending legacy clipboard shutdown engine creation failed");
+    execute_and_wait(engine, R"JS(
+        document.body.innerHTML = '<textarea id="pending-copy"></textarea>';
+        const editor = document.getElementById('pending-copy');
+        editor.addEventListener('keydown', event => {
+          if (event.metaKey && event.key.toLowerCase() === 'c') {
+            event.preventDefault();
+            document.execCommand('copy');
+          }
+        });
+        editor.addEventListener('copy', event => {
+          event.clipboardData.setData('text/plain', 'pending close');
+          event.preventDefault();
+        });
+        editor.focus();
+    )JS", "native-pending-legacy-clipboard-shutdown-setup.js");
+
+    keyboard_input(
+        engine, WEBSCENE_INPUT_KEY_DOWN, 'C', 31001U,
+        WEBSCENE_INPUT_MODIFIER_META);
+    webscene_engine_metrics metrics{};
+    webscene_engine_get_metrics(engine, &metrics);
+    wait_for_consumed_inputs(
+        engine, metrics.enqueued_inputs,
+        "pending legacy clipboard shutdown input was not consumed");
+    const auto request = take_typed_host_request(engine);
+    require(
+        request.kind == WEBSCENE_HOST_REQUEST_CLIPBOARD_WRITE_V1
+            && request.content_type == "text/plain"
+            && std::string(request.bytes.begin(), request.bytes.end())
+                == "pending close",
+        "pending legacy clipboard shutdown did not retain its host promise");
+
+    // A native window may close before the operating-system host completes a
+    // request. Destruction must release the pending persistent resolver while
+    // its V8 isolate is still alive.
+    webscene_engine_destroy(engine);
+}
+
 void test_clipboard_maximum_payload_gate(webscene_engine* engine)
 {
     constexpr size_t maximum_bytes = 16U * 1024U * 1024U;
diff --git a/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_tests.cpp b/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_tests.cpp
index e4313e059..5ddcc21ef 100644
--- a/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_tests.cpp
+++ b/experiments/WebScene.NativeEngine.Probe/tests/native_v8_runtime_tests.cpp
@@ -286,6 +286,12 @@ int main()
             webscene_engine_destroy(focused_engine);
             return 0;
         }
+        if (selected == "input-diagnostics-pointer-focus") {
+            test_document_direction_and_visibility_are_native_properties();
+            test_native_legacy_clipboard_completion_stress(nullptr);
+            test_native_pending_legacy_clipboard_shutdown(nullptr);
+            return 0;
+        }
         if (selected == "media-query-list") {
             auto* focused_engine = webscene_engine_create(0);
             require(focused_engine != nullptr, "focused engine creation failed");
@@ -925,6 +931,8 @@ int main()
     test_clipboard_write_text_host_handoff(engine);
     test_clipboard_read_host_completion(engine);
     test_native_clipboard_shortcut_events(engine);
+    test_native_legacy_clipboard_completion_stress(engine);
+    test_native_pending_legacy_clipboard_shutdown(engine);
     test_clipboard_maximum_payload_gate(engine);
     test_clipboard_small_round_trip_performance(engine);
     test_fullscreen_host_completion(engine);
diff --git a/scripts/build-native-engine-runtime.sh b/scripts/build-native-engine-runtime.sh
index c7c0a742c..08eeee851 100755
--- a/scripts/build-native-engine-runtime.sh
+++ b/scripts/build-native-engine-runtime.sh
@@ -383,6 +383,12 @@ elif [[ "$expected_kernel" == Linux ]]; then
     -DCMAKE_SHARED_LINKER_FLAGS=-fuse-ld=lld
   )
 fi
+if [[ "$expected_kernel" == Darwin && "$cmake_build_type" == Release ]]; then
+  # Keep line tables only until dsymutil has emitted the exact shipped
+  # binary's external symbols. strip removes them from the runtime before
+  # packaging, so diagnostics do not increase the installed footprint.
+  cmake_args+=("-DCMAKE_CXX_FLAGS_RELEASE=-O3 -DNDEBUG -gline-tables-only")
+fi
 cmake "${cmake_args[@]}"
 cmake --build "$build_dir" --config "$cmake_build_type" --parallel
 cmake -E copy_if_different "$icu_data" "$build_dir/icudtl.dat"
@@ -408,8 +414,6 @@ if [[ "$expected_kernel" == Darwin ]]; then
     echo "Native engine deployment target is '$actual_macos_deployment_target'; expected '$macos_deployment_target'." >&2
     exit 1
   fi
-fi
-if [[ "$expected_kernel" == Darwin && "$cmake_build_type" == RelWithDebInfo ]]; then
   native_dsym_path="$native_path.dSYM"
   cmake -E remove_directory "$native_dsym_path"
   dsymutil "$native_path" -o "$native_dsym_path"
@@ -417,6 +421,9 @@ if [[ "$expected_kernel" == Darwin && "$cmake_build_type" == RelWithDebInfo ]];
     echo "Native engine build did not produce '$native_dsym_path'." >&2
     exit 1
   fi
+  if [[ "$cmake_build_type" == Release ]]; then
+    strip -S "$native_path"
+  fi
 fi
 snapshot_path="$build_dir/webscene_bootstrap_snapshot.bin"
 snapshot_metadata_path="$build_dir/webscene_bootstrap_snapshot.meta"
diff --git a/tests/WebScene.Architecture.Tests/ReleaseCompatibilityGateTests.cs b/tests/WebScene.Architecture.Tests/ReleaseCompatibilityGateTests.cs
index 334a7eea3..df5281908 100644
--- a/tests/WebScene.Architecture.Tests/ReleaseCompatibilityGateTests.cs
+++ b/tests/WebScene.Architecture.Tests/ReleaseCompatibilityGateTests.cs
@@ -14,6 +14,40 @@ public void RuntimeBuildersRunTheCompleteRequiredCompatibilityProfile()
         AssertBuilderRunsCompleteRequiredProfile("build-native-engine-runtime.ps1");
     }
 
+    [Fact]
+    public void MacosReleaseRuntimePublishesExactBoundedNativeSymbols()
+    {
+        var builder = File.ReadAllText(Path.Combine(
+            s_repositoryRoot,
+            "scripts",
+            "build-native-engine-runtime.sh"));
+        Assert.Contains("-gline-tables-only", builder, StringComparison.Ordinal);
+        Assert.Contains("dsymutil \"$native_path\"", builder, StringComparison.Ordinal);
+        Assert.Contains("strip -S \"$native_path\"", builder, StringComparison.Ordinal);
+        var releaseOnlyGuard = builder.IndexOf(
+            "if [[ \"$expected_kernel\" == Darwin && \"$cmake_build_type\" == Release ]]; then",
+            StringComparison.Ordinal);
+        var lineTables = builder.IndexOf("-gline-tables-only", StringComparison.Ordinal);
+        var configure = builder.IndexOf("cmake \"${cmake_args[@]}\"", StringComparison.Ordinal);
+        Assert.True(
+            releaseOnlyGuard >= 0 && releaseOnlyGuard < lineTables && lineTables < configure,
+            "External symbol generation must be limited to the macOS Release package build.");
+        Assert.True(
+            builder.IndexOf("dsymutil \"$native_path\"", StringComparison.Ordinal)
+                < builder.IndexOf("strip -S \"$native_path\"", StringComparison.Ordinal),
+            "The exact runtime must be symbolized before its package copy is stripped, leaving no normal-path runtime cost.");
+
+        var workflow = File.ReadAllText(Path.Combine(
+            s_repositoryRoot,
+            ".github",
+            "workflows",
+            "native-runtime-packages.yml"));
+        Assert.Contains("name: Upload exact macOS native symbols", workflow, StringComparison.Ordinal);
+        Assert.Contains("path: artifacts/native-engine-runtime-build/**/*.dSYM/**", workflow, StringComparison.Ordinal);
+        Assert.Contains("compression-level: 9", workflow, StringComparison.Ordinal);
+        Assert.Contains("retention-days: 3", workflow, StringComparison.Ordinal);
+    }
+
     [Fact]
     public void RequiredProfileContainsTheEstablishedReleaseDenominator()
     {