fix: 优化模型价格文件更新策略

config/pricingSource.js

@@ -0,0 +1,17 @@
+const repository =
+  process.env.PRICE_MIRROR_REPO || process.env.GITHUB_REPOSITORY || 'Wei-Shaw/claude-relay-service'
+const branch = process.env.PRICE_MIRROR_BRANCH || 'price-mirror'
+const pricingFileName = process.env.PRICE_MIRROR_FILENAME || 'model_prices_and_context_window.json'
+const hashFileName = process.env.PRICE_MIRROR_HASH_FILENAME || 'model_prices_and_context_window.sha256'
+
+const baseUrl = process.env.PRICE_MIRROR_BASE_URL
+  ? process.env.PRICE_MIRROR_BASE_URL.replace(/\/$/, '')
+  : `https://raw.githubusercontent.com/${repository}/${branch}`
+
+module.exports = {
+  pricingFileName,
+  hashFileName,
+  pricingUrl:
+    process.env.PRICE_MIRROR_JSON_URL || `${baseUrl}/${pricingFileName}`,
+  hashUrl: process.env.PRICE_MIRROR_HASH_URL || `${baseUrl}/${hashFileName}`
+}