fix(lint): avoid unpacking nullable find_by_id in service layers

Use row.update() instead of re-querying after update to avoid
pyright errors on dict | None unpacking.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ImTotem

src/bcsd_api/apply/service.py

@@ -116,7 +116,8 @@ def confirm_payment(
     if row["status"] != "납부_대기":
         raise BadRequest("application is not in payment pending status")
     app_repo.update_fields(app_id, {"status": "납부_완료", "updated_at": _now()})
-    return ApplicationResponse(**app_repo.find_by_id(app_id))
+    row["status"] = "납부_완료"
+    return ApplicationResponse(**row)
 
 
 def approve(
@@ -139,7 +140,8 @@ def approve(
             "approved_by": admin_id, "updated_at": now,
         })
         member_repo.update_status(row["member_id"], new_status)
-        result.append(ApplicationResponse(**app_repo.find_by_id(app_id)))
+        row.update({"status": "승인", "approved_at": now, "approved_by": admin_id})
+        result.append(ApplicationResponse(**row))
     return result
 
 

src/bcsd_api/recruit/service.py

@@ -29,11 +29,12 @@ def create_period(
 def update_period(
     repo: PgRecruitRepository, period_id: str, req: UpdatePeriodRequest,
 ) -> PeriodResponse:
-    _get_or_raise(repo, period_id)
+    row = _get_or_raise(repo, period_id)
     updates = req.model_dump(exclude_none=True)
     updates["updated_at"] = _now()
     repo.update_fields(period_id, updates)
-    return PeriodResponse(**repo.find_by_id(period_id))
+    row.update(updates)
+    return PeriodResponse(**row)
 
 
 def list_periods(repo: PgRecruitRepository) -> list[PeriodResponse]: