refactor: 각 어댑터터별 리펙토링 진행

.github/workflows/jpa-nightly.yml

@@ -119,10 +119,14 @@ jobs:
             src/**/*.gradle
             src/**/gradle-wrapper.properties
             src/**/gradle.lockfile
-      - name: Measure pool saturation and REQUIRES_NEW pressure
+      - name: Verify pool saturation and REQUIRES_NEW connection behaviour
         working-directory: src
-        # Machine-dependent bounds are reported rather than asserted unless explicitly enabled, so a
-        # noisy shared runner does not produce a red build that means nothing.
+        # A behaviour contract, not a measurement. This step used to switch assertions off with an
+        # explicit property and call the result a certification, so the only threshold it ever
+        # asserted was that thresholds were not being asserted. What
+        # it checks now — that REQUIRES_NEW needs two connections per concurrent thread, that a
+        # saturated pool reports its pending count, that a caller waits rather than proceeding
+        # without a connection — is true on any runner, so there is nothing to switch off.
         run: >-
           ./gradlew
           :adapter:outbound:persistence-jpa:jpaPlatformPoolContractTest