Run executables directly (#645)

- Apps can be launched directly from file paths (including Files app support)
- Added executable detection to identify unsupported or invalid binaries before launch.
- App startup is now streamlined through separate registered-app and direct-execution interfaces.
- Existing app launch points were migrated to the updated startup APIs.

Modules/app-module/source/execute.cpp

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <app/execute.h>
+
+#include <app/loader.h>
+#include <app/location.h>
+#include <app/private/manager_internal.h>
+
+#include <service/instance.h>
+#include <service/manager.h>
+
+namespace {
+
+// Same lookup as scheduler.cpp's own (private) find_loader_api() - duplicated rather than
+// shared since it's a handful of lines and neither file depends on the other.
+const char* loader_service_id_for(AppLocationType type) {
+    return (type == APP_LOCATION_MEMORY) ? APP_LOADER_MEMORY_SERVICE_ID : APP_LOADER_PATH_SERVICE_ID;
+}
+
+const AppLoaderApi* find_loader_api(AppLocationType type) {
+    ServiceInstance* instance = service_manager_find_instance(loader_service_id_for(type));
+    if (instance == nullptr) {
+        return nullptr;
+    }
+    return static_cast<const AppLoaderApi*>(service_instance_get_data(instance));
+}
+
+} // namespace
+
+extern "C" {
+
+error_t app_execute(AppLocation location, AppStackConfig stack, int argc, const char* const argv[], AppInstanceId* out_app_instance_id) {
+    return app_manager_start_internal(nullptr, location, stack, 0, argc, argv, nullptr, 0, out_app_instance_id);
+}
+
+error_t app_execute_for_result(AppLocation location, AppStackConfig stack, int argc, const char* const argv[], AppInstanceId parent_instance_id, AppInstanceId* out_app_instance_id) {
+    return app_manager_start_internal(nullptr, location, stack, parent_instance_id, argc, argv, nullptr, 0, out_app_instance_id);
+}
+
+error_t app_execute_with_streams(AppLocation location, AppStackConfig stack, int argc, const char* const argv[], const AppStreamBinding* bindings, size_t binding_count, AppInstanceId* out_app_instance_id) {
+    return app_manager_start_internal(nullptr, location, stack, 0, argc, argv, bindings, binding_count, out_app_instance_id);
+}
+
+error_t app_execute_for_result_with_streams(AppLocation location, AppStackConfig stack, int argc, const char* const argv[], const AppStreamBinding* bindings, size_t binding_count, AppInstanceId parent_instance_id, AppInstanceId* out_app_instance_id) {
+    return app_manager_start_internal(nullptr, location, stack, parent_instance_id, argc, argv, bindings, binding_count, out_app_instance_id);
+}
+
+bool app_is_executable(AppLocation location) {
+    const AppLoaderApi* loader = find_loader_api(location.type);
+    if (loader == nullptr || loader->is_executable == nullptr) {
+        return false;
+    }
+    return loader->is_executable(location);
+}
+
+} // extern "C"