refactor: make frontend a pure presentation layer fetching from backend API

Server components now fetch composed data from the backend instead of
directly querying SQLite and external APIs. Removes better-sqlite3
dependency from the frontend entirely.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/db/queries.ts

@@ -1,11 +1,8 @@
 import type Database from "better-sqlite3";
 import { getDb } from "./index";
 
-export interface DayData {
-  isOpen: boolean;
-  hoursLabel: string | null;
-  specialType: string | null;
-}
+import type { DayData } from "../../../lib/types";
+export type { DayData };
 
 interface DayRow {
   park_id: string;