refactor(build,ci): 현재 상태 검증을 걷어내고 불변조건만 남기는 검증 표면 축소

외부 리뷰("현재 상태를 유지하기 위한 검증이 너무 많고, 그 검증 자체를
다시 검증하는 구조까지 생겼다")를 설계 문서로 정리하고 코드로 반영한다.
설계·판단 근거는 docs/superpowers/specs/2026-09-16-verification-surface-reduction-design.md.

삭제
- .github/ci-gate-matrix.yml(1,025줄) + verify-gate-matrix.sh(568줄):
  Gradle task graph와 workflow graph에 이미 있는 정보의 3중 복제
- verify-gradle-wrapper.sh(799줄): workflow 바이트 해시 잠금.
  wrapper 검증은 gradle/actions/wrapper-validation(full SHA 핀)에 위임
- DeveloperExperienceContractTest 등의 CI YAML mutation 테스트:
  애플리케이션 test suite가 GitHub Actions YAML 파서를 검증하던 계층 역전
- 문서 drift 파서: verifyReadmeCommands, verifyRunbookReferences,
  verifyDocumentedLeafCount, verifyTestSourceSetRegistry
- 빈 레지스트리를 지키던 커스텀 YAML 파서: verifyTrivyignore,
  verifyQuarantineSunset, flaky-quarantine.yaml
- verifyConfigurationPropertiesProcessor, verifyOneTypePerFile:
  각각 ca.spring-config convention과 Checkstyle OneTopLevelClass가 대체
- 정상 입력으로도 성공할 수 없던 messaging always-fail task
- ModuleRegistry의 JSON 필드 집합 정확 일치, sample-portfolio negative guard

이동
- java/quality/spring 공통 설정을 configure(subprojects) 블록에서
  ca.java-conventions / ca.quality-conventions / ca.java-library /
  ca.spring-library convention plugin으로
- 아키텍처 검증을 ca.architecture로, JPA·messaging qualification을
  gradle/qualification/ 아래로, verifyEnvKeys를 :app-bootstrap 소유로

완화
- Git revision은 releaseCheck·아카이브 생성에서만 요구. 일반 빌드는 SNAPSHOT
- SpotBugs/FindSecBugs는 로컬 check에서 빼고 qualityCheck 레인으로

task 계층
- leaf check는 그 leaf만. architectureCheck / qualityCheck /
  configContractCheck / integrationCheck / ci / releaseCheck로 이름 분리

CI
- _reusable-gradle.yml 신규. checkout + wrapper validation + JDK/캐시 공통화
- fileserver-release.yml -> fileserver-certification.yml (CD가 아니라 certification)
- GitHub Actions = CI + artifact, Argo CD = CD 경계를 docs/ci-cd/boundary.md로 고정

순증감 +3,274 / -7,483.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/adapter/outbound/notification/build.gradle

@@ -1,3 +1,6 @@
+apply plugin: 'ca.spring-library'
+apply plugin: 'ca.spring-config'
+
 dependencies {
     implementation project(':application-core')
     implementation project(':shared-contract')
@@ -44,7 +47,6 @@ dependencies {
         exclude group: 'com.fasterxml.jackson.dataformat', module: 'jackson-dataformat-yaml'
     }
 
-    annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
 
     testImplementation 'io.projectreactor:reactor-test'
 }
@@ -58,3 +60,22 @@ dependencyPolicy {
     absent 'tools.jackson.dataformat:jackson-dataformat-yaml',
             because: 'the Jackson 3 coordinate of the same parser, excluded for the same reason'
 }
+
+// The three notification gates run with the leaf they are about.
+//
+// All three existed and passed for months while nothing ran them, and the cost was measurable the
+// first time they were: twenty-nine environment variables bound in application.yml were absent from
+// the configuration reference — the whole SMTP relay and all eight key-material purposes — and
+// thirteen public types had entered the notification API surface without the reviewed baseline
+// recording any of them.
+//
+// They ran on all 62 leaves once, which reached them 62 times and told the developer who changed
+// :domain-core about the notification surface. An API surface baseline and a configuration reference
+// for one adapter are that adapter's contract, so they belong to the command a developer runs after
+// changing it — and the wiring is declared here, in that leaf, rather than reached into from the
+// root. `.github/workflows/notification-platform.yml` also invokes all three by name.
+tasks.named('check') {
+    dependsOn rootProject.tasks.named('verifyNotificationApiSurface')
+    dependsOn rootProject.tasks.named('verifyNotificationConfiguration')
+    dependsOn rootProject.tasks.named('verifyNotificationEvidence')
+}