Use internal mock host for release assets

tests/integration/docker-compose.test.yml

@@ -9,6 +9,7 @@ services:
       - "8080:8080"
     environment:
       - PORT=8080
+      - MOCK_BASE_URL=http://mock-github:8080
       # Control test scenarios via environment variables
       - MOCK_CHECKSUM_ERROR=${MOCK_CHECKSUM_ERROR:-false}
       - MOCK_NETWORK_ERROR=${MOCK_NETWORK_ERROR:-false}

tests/integration/mock-github-server/main.go

@@ -107,7 +107,7 @@ func main() {
 	}
 
 	limiter := newRateLimiter()
-	baseURL := fmt.Sprintf("http://localhost:%s", port)
+	baseURL := getenvDefault("MOCK_BASE_URL", fmt.Sprintf("http://mock-github:%s", port))
 
 	// Environment-controlled behavior
 	checksumError := os.Getenv("MOCK_CHECKSUM_ERROR") == "true"