docs(container): 리팩토링 및 개선점에 대한 문서 반영

Author: yyubin

README.md

@@ -172,7 +172,7 @@ public class ChatSocket {
 **Reports:** [Tests](https://yyubin.github.io/sprout/tests/) ·
 [Coverage](https://yyubin.github.io/sprout/coverage/)
 
-**577 tests, 0 failures (100% pass, Gradle 8.10.1 · 2025‑09‑26)**
+**658 tests, 0 failures (100% pass, Gradle 8.10.1 · 2025‑10-21)**
 
 **Test Coverage (Jacoco):**
 - **Line Coverage: 85%**

README_ko.md

@@ -174,7 +174,7 @@ public class ChatSocket {
 **리포트:** [테스트](https://yyubin.github.io/sprout/tests/) ·
 [커버리지](https://yyubin.github.io/sprout/coverage/)
 
-**577개 테스트, 0개 실패 (100% 통과, Gradle 8.10.1 · 2025‑09‑26)**
+**658개 테스트, 0개 실패 (100% 통과, Gradle 8.10.1 · 2025‑10‑21)**
 
 **테스트 커버리지 (Jacoco):**
 - **라인 커버리지: 85%**