feat: add Hono backend API server with tiered scheduler

Standalone Node.js backend that owns the SQLite database and serves
composed data via REST endpoints. Replaces the shell-scheduled scraper
with in-process node-cron tiered scheduling.

Backend structure:
- Hono HTTP server on port 3001 with CORS and request logging
- Singleton SQLite connection with WAL mode
- In-memory TTL cache for Queue-Times and fetchToday responses
- Comparison check on fetchToday (read-before-write, only upserts on change)

API endpoints:
- GET /api/calendar/week — week schedule + live ride counts for all parks
- GET /api/calendar/:parkId/month — month calendar for one park
- GET /api/parks — park list with metadata
- GET /api/parks/:id — single park detail
- GET /api/parks/:id/rides — live rides with Queue-Times/schedule fallback
- GET /api/status — health check, scrape stats
- POST /api/scrape/trigger — manual scrape (scope: today/month/upcoming/full)

Scheduler tiers:
- Tier 1: today — hourly (Mar-Dec)
- Tier 2: current month — every 6 hours
- Tier 3: upcoming — twice daily (3 AM + 3 PM)
- Tier 4: full year — daily at 3 AM

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

backend/package.json

@@ -0,0 +1,24 @@
+{
+  "name": "sixflags-backend",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc",
+    "start": "node dist/index.js",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "@hono/node-server": "^2.0.0",
+    "better-sqlite3": "^12.8.0",
+    "hono": "^4.7.0",
+    "node-cron": "^3.0.3"
+  },
+  "devDependencies": {
+    "@types/better-sqlite3": "^7.6.13",
+    "@types/node": "^22",
+    "@types/node-cron": "^3.0.11",
+    "tsx": "^4.21.0",
+    "typescript": "^5"
+  }
+}