Implement frontend routing and API fallback handling; add dependencies for include_dir and mime_guess

apps/api/src/routes/api.rs

@@ -0,0 +1,11 @@
+use axum::{Router, response::IntoResponse, routing::any};
+
+pub fn get_api_router() -> Router {
+    Router::new()
+        // explicit fallback for unmatched API routes
+        .route("/{*wildcard}", any(api_fallback_handler))
+}
+
+async fn api_fallback_handler() -> impl IntoResponse {
+    (axum::http::StatusCode::NOT_FOUND, "API route not found").into_response()
+}