refactor: hardcode API IDs and coaster lists, remove Playwright discovery

Embed Six Flags API IDs directly in the park registry and snapshot
coaster lists from park-meta.json into a TypeScript module. This
eliminates the Playwright-based discovery script, RCDB scraper, and
runtime dependency on park-meta.json — preparing for the backend
API transition.

- Add apiId field to Park type and all 24 park entries
- Create lib/coaster-data.ts with hardcoded coaster lists
- Update page components to use park.apiId and new getCoasterSet()
- Remove scripts/discover.ts, lib/scrapers/rcdb.ts, lib/park-meta.ts
- Remove data/park-meta.json from shared volume
- Remove playwright devDependency and discover npm script
- Simplify scripts/scrape.ts (no RCDB, no discovery checks)

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

lib/scrapers/sixflags.ts

@@ -1,11 +1,8 @@
 /**
- * Six Flags scraper — calls the internal CloudFront operating-hours API directly.
+ * Six Flags API client — calls the internal CloudFront operating-hours API.
  *
  * API: https://d18car1k0ff81h.cloudfront.net/operating-hours/park/{apiId}?date=YYYYMM
- * Returns full month data in one request — no browser needed.
- *
- * Each park has a numeric API ID that must be discovered first (see scripts/discover.ts).
- * Once stored in the DB, this scraper never touches a browser again.
+ * Returns full month data in one request.
  *
  * Rate limiting: on 429/503, exponential backoff (30s → 60s → 120s), MAX_RETRIES attempts.
  */
@@ -309,7 +306,6 @@ export async function scrapeRidesForDay(
 
 /**
  * Fetch operating hours for an entire month in a single API call.
- * apiId must be pre-discovered via scripts/discover.ts.
  */
 export async function scrapeMonth(
   apiId: number,
@@ -325,8 +321,7 @@ export async function scrapeMonth(
 }
 
 /**
- * Fetch park info for a given API ID (used during discovery to identify park type).
- * Uses the current month so there's always some data.
+ * Fetch park info for a given API ID. Uses the current month so there's always some data.
  */
 export async function fetchParkInfo(
   apiId: number