fix: add missing import for inferUpstreamErrorStatusCodeFromText

The function inferUpstreamErrorStatusCodeFromText was used in
response-handler.ts but was not imported, causing a TypeScript
compilation error during build.

Fixed:
- Added inferUpstreamErrorStatusCodeFromText to imports from @/lib/utils/upstream-error-detection

CI Run: https://github.com/ding113/claude-code-hub/actions/runs/22033028838

src/app/v1/_lib/proxy/response-handler.ts

@@ -12,7 +12,10 @@ import type { CostBreakdown } from "@/lib/utils/cost-calculation";
 import { calculateRequestCost, calculateRequestCostBreakdown } from "@/lib/utils/cost-calculation";
 import { hasValidPriceData } from "@/lib/utils/price-data";
 import { isSSEText, parseSSEData } from "@/lib/utils/sse";
-import { detectUpstreamErrorFromSseOrJsonText } from "@/lib/utils/upstream-error-detection";
+import {
+  detectUpstreamErrorFromSseOrJsonText,
+  inferUpstreamErrorStatusCodeFromText,
+} from "@/lib/utils/upstream-error-detection";
 import {
   updateMessageRequestCost,
   updateMessageRequestDetails,