chore: move App and app related code to app layer

src/app/types/ambient.d.ts

@@ -0,0 +1,33 @@
+declare module '*.svelte' {
+    import type { ComponentProps as SvelteComponentProps, ComponentType, Snippet } from 'svelte';
+    import type { HTMLAttributes } from 'svelte/elements';
+
+    interface Component {
+        new(options: {
+            target: HTMLElement;
+            props?: Record<string, unknown>;
+            intro?: boolean;
+        }): {
+            $on: (event: string, handler: (...args: unknown[]) => unknown) => void;
+            $destroy: () => void;
+            $set: (props: Record<string, unknown>) => void;
+        };
+    }
+
+    export default Component;
+}
+
+declare module '*.svg' {
+    const content: string;
+    export default content;
+}
+
+declare module '*.png' {
+    const content: string;
+    export default content;
+}
+
+declare module '*.jpg' {
+    const content: string;
+    export default content;
+}