In
`@app/src/main/java/com/konkuk/medicarecall/data/repositoryimpl/EldersHealthInfoRepositoryImpl.kt`:
- Around line 45-51: The call to elderRegisterService.postElderHealthInfo(...)
uses handleResponse(), which fails because postElderHealthInfo returns
Response<Unit> (204 No Content with null body); replace the call to
handleResponse() with handleNullableResponse() so a null body is treated as a
successful response, i.e. update the invocation on the result of
elderRegisterService.postElderHealthInfo(elderInfo.elderId, elder) to use
handleNullableResponse(), keeping the surrounding code
(ElderHealthRegisterRequestDto construction and refresh() call) unchanged.

In
`@app/src/main/java/com/konkuk/medicarecall/data/repositoryimpl/SetCallRepositoryImpl.kt`:
- Around line 15-20: saveForElder is calling
service.saveCareCallTimes(...).handleResponse(), which throws on 204 No Content
because ResponseHandler expects a non-null body; change the call to use
handleNullableResponse() instead (i.e., replace handleResponse() with
handleNullableResponse() in saveForElder) or update the ResponseHandler to treat
Unit/empty bodies as success (special-case when T is Unit or
response.code()==204) so a null body doesn't raise error; specifically look for
saveForElder, service.saveCareCallTimes, handleResponse, handleNullableResponse
and adjust the call or ResponseHandler logic accordingly.

In `@app/src/main/java/com/konkuk/medicarecall/data/util/ResponseHandler.kt`:
- Around line 6-11: handleResponse() currently throws when body() is null, which
breaks endpoints that return Response<Unit> on 204 No Content; update
handleResponse (or replace calls with handleNullableResponse) to treat null body
as valid when the response code is 204 or when T is Unit: in the success branch,
if body() != null return it, otherwise if (code() == 204 || T represents
kotlin.Unit) return Unit cast to T, else throw the existing error; apply this
change in the handleResponse function used by
SetCallService.saveCareCallTimes(), HomeService.requestImmediateCareCall(),
EldersInfoService.deleteElderSettings(), ElderRegisterService methods,
AuthService.requestCertificationCode()/logout(), and FcmService methods (or
switch those callers to handleNullableResponse()).

In `@REFACTORING_ANALYSIS.md`:
- Around line 41-62: The markdown code fences in REFACTORING_ANALYSIS.md are
missing language identifiers (violates MD040); update each fenced block (e.g.,
the project tree blocks shown in the diff) to add an appropriate language tag
such as ```text or ```kotlin/```gradle where applicable, ensuring opening fences
include the language and closing fences remain ```; apply the same change to the
other occurrences called out in the comment (around the blocks at lines ~71-74,
~171-181, and ~282-286) so all fenced code blocks have language specifiers.
- Around line 26-33: The Markdown table block lacks surrounding blank lines,
violating MD058; add one empty line before the table start ("| 항목 | 수치 |") and
one empty line after the table end ("| 테스트 코드 | 3개 (극히 부족) |") so the table is
separated from surrounding paragraphs and complies with markdownlint.

In
`@app/src/main/java/com/konkuk/medicarecall/data/repositoryimpl/HomeRepositoryImpl.kt`:
- Around line 24-25: getHomeSummary currently returns HomeResponseDto directly
from HomeRepositoryImpl.getHomeSummary by calling
homeService.getHomeSummary(elderId).handleResponse(), which breaks consistency
with other repository methods and can propagate exceptions; update
HomeRepository and HomeRepositoryImpl.getHomeSummary to return
Result<HomeResponseDto> and wrap the service call in runCatching {
homeService.getHomeSummary(elderId).handleResponse() } so callers receive a
Result and exceptions are captured instead of thrown.

In
`@app/src/main/java/com/konkuk/medicarecall/data/repositoryimpl/UserRepositoryImpl.kt`:
- Around line 18-24: updateMyInfo in UserRepositoryImpl currently calls
settingService.updateMyInfo(...).handleResponse(), but if the server returns
204/empty body this will cause handleResponse() to throw a "response is null"
error; check the actual SettingService.updateMyInfo API contract and if it can
return an empty body, replace handleResponse() with handleNullableResponse() for
updateMyInfo in UserRepositoryImpl (and update the comment near SettingService
line 18 if needed) so the nullable/empty response is handled safely while
leaving getMyInfo() unchanged.