refactor: simplify pricing tables to USD-only

- Remove KRW pricing calculations from all pricing tables
- Simplify pricing table to store only wholesale USD prices
- Simplify anvil_pricing to store only retail USD prices
- Remove KRW environment variables (KRW_EXCHANGE_RATE, KRW_MARGIN_RATE)
- Remove KRW functions from constants.ts
- Update GPU/G8/VPU pricing repositories to match
- Add Anvil tables and repositories for branded product support

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

wrangler.toml

@@ -21,11 +21,6 @@ CACHE_TTL_SECONDS = "300"
 LOG_LEVEL = "info"
 CORS_ORIGIN = "*"
 
-# KRW Pricing Configuration (can be changed without redeployment)
-KRW_EXCHANGE_RATE = "1450"
-KRW_VAT_RATE = "1.1"
-KRW_MARKUP_RATE = "1.1"
-
 # Cron Triggers
 [triggers]
 crons = [