Refactor app loading and window management (#609)

Modules/app-module/include/app/manifest.h

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include "location.h"
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Broad classification of an app, used for grouping/launcher presentation. */
+enum AppCategory {
+    APP_CATEGORY_SYSTEM,
+    APP_CATEGORY_SETTINGS,
+    APP_CATEGORY_USER,
+};
+
+/** Bit flags for AppManifest::flags. */
+enum AppManifestFlags {
+    /** Excluded from generic app-browsing UIs (AppList, Settings) - for apps only ever reached
+     * by direct navigation (modal dialogs, detail views that require parameters, wizard/
+     * bootstrap steps). */
+    APP_MANIFEST_FLAG_HIDDEN = 0b00000001,
+};
+
+/** Describes a registrable app. One manifest exists per app id. */
+struct AppManifest {
+    /** Unique app identifier. Should never be NULL. */
+    const char* id;
+    /** Human-readable name. Should never be NULL. */
+    const char* name;
+    enum AppCategory category;
+    struct AppLocation location;
+    /** Bitmask of AppManifestFlags. Most apps should leave this 0. */
+    uint8_t flags;
+};
+
+#ifdef __cplusplus
+}
+#endif