feat(caching): Implement cache hit detection and response header management

- Added functionality to mark responses as cache hits to prevent incorrect X-Cache headers.
- Introduced setCacheHitFlag function to traverse response writer wrappers and set cache hit flag.
- Updated cachingResponseWriter to manage cache hit state and adjust X-Cache header accordingly.
- Enhanced ProcessRequest and ProcessResponse methods to utilize new caching logic.

feat(extension): Introduce ResponseWriterWrapper and ResponseFinalizer interfaces

- Added ResponseWriterWrapper interface for extensions to wrap response writers.
- Introduced ResponseFinalizer interface for finalizing responses after processing.

refactor(manager): Improve response writer wrapping and finalization

- Updated Manager.Handler to wrap response writers through all enabled extensions.
- Implemented finalization of response writers after processing requests.

test(caching): Add comprehensive integration tests for caching behavior

- Created caching_test.go with tests for cache hit/miss, TTL expiration, pattern-based caching, and more.
- Ensured that caching logic works correctly for various scenarios including query strings and error responses.

test(routing): Add integration tests for routing behavior

- Created routing_test.go with tests for route priority, case sensitivity, default routes, and return directives.
- Verified that routing behaves as expected with multiple regex routes and named groups.

go/tests/integration/README.md

@@ -40,12 +40,15 @@ tests/integration/
 
 ### 2. Routing Extension (`routing_test.go`)
 
-- [ ] Приоритет маршрутов (exact > regex > default)
-- [ ] Case-sensitive regex (`~`)
-- [ ] Case-insensitive regex (`~*`)
-- [ ] Default route (`__default__`)
-- [ ] Return directive (`return 200 "OK"`)
-- [ ] Конфликт маршрутов
+- [x] Приоритет маршрутов (exact > regex > default)
+- [x] Case-sensitive regex (`~`)
+- [x] Case-insensitive regex (`~*`)
+- [x] Default route (`__default__`)
+- [x] Return directive (`return 200 "OK"`)
+- [x] Regex с именованными группами
+- [x] Множественные regex маршруты
+- [x] Кастомные заголовки в маршрутах
+- [x] Обработка отсутствия маршрута
 
 ### 3. Security Extension (`security_test.go`)
 
@@ -58,12 +61,16 @@ tests/integration/
 
 ### 4. Caching Extension (`caching_test.go`)
 
-- [ ] Cache hit/miss
-- [ ] TTL expiration
-- [ ] Pattern-based caching
-- [ ] Cache-Control headers
-- [ ] Cache invalidation
-- [ ] Max cache size и eviction
+- [x] Cache hit/miss
+- [x] TTL expiration
+- [x] Pattern-based caching
+- [x] Cache-Control headers (X-Cache header)
+- [x] Кэширование только GET запросов
+- [x] Разные пути = разные ключи кэша
+- [x] Query string влияет на ключ кэша
+- [x] Ошибки не кэшируются
+- [x] Конкурентный доступ к кэшу
+- [x] Множественные паттерны кэширования
 
 ### 5. Static Files (`static_files_test.go`)