docs: describe project structure

src/domain/photo.ts

@@ -0,0 +1,9 @@
+export interface Photo {
+  id: string;
+  fileName: string;
+  capturedAt: string | null;
+  latitude: number | null;
+  longitude: number | null;
+  thumbnailUrl: string | null;
+}
+

src/domain/route.ts

@@ -0,0 +1,7 @@
+export interface RoutePoint {
+  photoId: string;
+  capturedAt: string;
+  latitude: number;
+  longitude: number;
+}
+

src/features/map/map-service.ts

@@ -0,0 +1,6 @@
+import type { RoutePoint } from "../../domain/route.js";
+
+export function buildRoute(points: RoutePoint[]): RoutePoint[] {
+  return points.slice().sort((a, b) => a.capturedAt.localeCompare(b.capturedAt));
+}
+

src/features/photos/photo-service.ts

@@ -0,0 +1,6 @@
+import type { Photo } from "../../domain/photo.js";
+
+export function listPhotos(): Photo[] {
+  return [];
+}
+