fix(notification): close the static-analysis findings on the merged tree

Checkstyle and SpotBugs run in the module's `check` task, not in `test`, so
these only surfaced once the platform was verified against the merged tree.

- MissingSwitchDefault on the admin runtime-state switch. The enum is
  exhaustive, so the default is unreachable today; it throws rather than
  falling through, so a state added later fails loudly instead of silently
  leaving the runtime in whatever state it already had.
- ConstantName on the two audit loggers: the checkstyle pattern allows
  `log`, `logger` or UPPER_SNAKE, and this class needs two named sinks.
- DMI_RANDOM_USED_ONLY_ONCE in three Web Push fixtures. A fresh SecureRandom
  per call re-seeds from the OS every time, which on a constrained CI runner
  can block on entropy.

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

src/adapter/outbound/notification/src/main/java/dev/caskeleton/adapter/outbound/notification/platform/admin/NotificationAdminServiceImpl.java

@@ -293,6 +293,9 @@ public final class NotificationAdminServiceImpl implements NotificationAdminServ
       case DEGRADED -> runtime.markDegraded(command.reason());
       case THROTTLED -> runtime.markThrottled();
       case AUTHENTICATION_FAILED -> runtime.markAuthenticationFailed(command.reason());
+      // Unreachable while the enum is exhaustive; present so a state added later fails loudly here
+      // rather than silently leaving the runtime in whatever state it was already in.
+      default -> throw new IllegalStateException("unhandled provider runtime state");
     }
 
     AdminOperationResult result =

src/adapter/outbound/notification/src/main/java/dev/caskeleton/adapter/outbound/notification/platform/observation/LoggingNotificationAudit.java

@@ -22,13 +22,13 @@ import org.slf4j.LoggerFactory;
 public final class LoggingNotificationAudit
     implements NotificationAuditPort, NotificationSecurityAuditPort {
 
-  private static final Logger audit = LoggerFactory.getLogger("notification.audit");
-  private static final Logger security = LoggerFactory.getLogger("notification.security");
+  private static final Logger AUDIT = LoggerFactory.getLogger("notification.audit");
+  private static final Logger SECURITY = LoggerFactory.getLogger("notification.security");
 
   @Override
   public void record(NotificationAuditEvent event) {
     Objects.requireNonNull(event, "event");
-    audit.info(
+    AUDIT.info(
         "action={} actor={} reason={} operationId={} occurredAt={} attributes={}",
         event.action(),
         event.actorRef(),
@@ -43,7 +43,7 @@ public final class LoggingNotificationAudit
     Objects.requireNonNull(profileId, "profileId");
     // The payload is deliberately absent: a forged callback must not get its content into the log
     // just by being rejected.
-    security.warn(
+    SECURITY.warn(
         "event=callback_signature_rejected providerProfile={} reason={}",
         profileId.value(),
         reasonCode);
@@ -52,7 +52,7 @@ public final class LoggingNotificationAudit
   @Override
   public void callbackRejectedByLimit(ProviderProfileId profileId, String reasonCode) {
     Objects.requireNonNull(profileId, "profileId");
-    security.warn(
+    SECURITY.warn(
         "event=callback_rejected_by_limit providerProfile={} reason={}",
         profileId.value(),
         reasonCode);

src/adapter/outbound/notification/src/test/java/dev/caskeleton/adapter/outbound/notification/platform/provider/webpush/WebPushCryptoTest.java

@@ -41,6 +41,9 @@ class WebPushCryptoTest {
   private static final Clock CLOCK =
       Clock.fixed(Instant.parse("2026-08-14T00:00:00Z"), ZoneOffset.UTC);
   private static final URI ENDPOINT = URI.create("https://push.example.com/send/abc123");
+  // One instance: a fresh SecureRandom per call re-seeds from the OS each time, which is slower
+  // and, on a constrained CI runner, can block on entropy.
+  private static final SecureRandom RANDOM = new SecureRandom();
 
   @Test
   void payloadIsEncryptedForTheSubscriptionAndDecryptsBackToThePlaintext() throws Exception {
@@ -221,7 +224,7 @@ class WebPushCryptoTest {
 
   private static byte[] authSecret() {
     byte[] secret = new byte[16];
-    new SecureRandom().nextBytes(secret);
+    RANDOM.nextBytes(secret);
     return secret;
   }
 

src/adapter/outbound/notification/src/test/java/dev/caskeleton/adapter/outbound/notification/platform/provider/webpush/WebPushProviderAdapterTest.java

@@ -35,6 +35,10 @@ class WebPushProviderAdapterTest {
   private static final Clock CLOCK =
       Clock.fixed(Instant.parse("2026-08-14T00:00:00Z"), ZoneOffset.UTC);
 
+  // One instance: a fresh SecureRandom per call re-seeds from the OS each time, which is slower
+  // and, on a constrained CI runner, can block on entropy.
+  private static final SecureRandom RANDOM = new SecureRandom();
+
   private final ProviderFaultHarness harness = new ProviderFaultHarness();
   private final ContactPointProtector protector =
       new AesGcmContactPointProtector(SecurityFixtures.keys());
@@ -115,7 +119,7 @@ class WebPushProviderAdapterTest {
 
   @Test
   void payloadEncryptionRoundTripsThroughTheSubscriptionKeys() {
-    var encryptor = new Rfc8291Aes128GcmEncryptor(new SecureRandom());
+    var encryptor = new Rfc8291Aes128GcmEncryptor(RANDOM);
     var subscription = subscription();
 
     var encrypted =
@@ -135,7 +139,7 @@ class WebPushProviderAdapterTest {
     return new WebPushNotificationProviderAdapter(
         new JdkNotificationHttpGateway(Duration.ofSeconds(2)),
         new WebPushRequestMapper(
-            new Rfc8291Aes128GcmEncryptor(new SecureRandom()),
+            new Rfc8291Aes128GcmEncryptor(RANDOM),
             // Signing needs a PKCS#8 EC key, which VapidJwtSignerTest covers; this keeps the
             // transport test about TTL, encryption and status mapping.
             (endpoint, signingKey, publicKey) -> "vapid t=stub-token, k=" + publicKey,
@@ -163,7 +167,7 @@ class WebPushProviderAdapterTest {
       generator.initialize(new ECGenParameterSpec("secp256r1"));
       KeyPair pair = generator.generateKeyPair();
       byte[] authSecret = new byte[16];
-      new SecureRandom().nextBytes(authSecret);
+      RANDOM.nextBytes(authSecret);
       return new WebPushSubscriptionValue(
           URI.create(harness.baseUri() + "/push/subscription-1"),
           Rfc8291Aes128GcmEncryptor.encodePoint((ECPublicKey) pair.getPublic()),

src/adapter/outbound/notification/src/test/java/dev/caskeleton/adapter/outbound/notification/platform/testkit/ContractAdapters.java

@@ -61,6 +61,10 @@ import java.util.Optional;
  */
 public final class ContractAdapters {
 
+  // One instance: a fresh SecureRandom per call re-seeds from the OS each time, which is slower
+  // and, on a constrained CI runner, can block on entropy.
+  private static final SecureRandom RANDOM = new SecureRandom();
+
   private static final Clock CLOCK =
       Clock.fixed(Instant.parse("2026-08-14T00:00:00Z"), ZoneOffset.UTC);
 
@@ -186,7 +190,7 @@ public final class ContractAdapters {
         new WebPushNotificationProviderAdapter(
             new JdkNotificationHttpGateway(Duration.ofSeconds(2)),
             new WebPushRequestMapper(
-                new Rfc8291Aes128GcmEncryptor(new SecureRandom()),
+                new Rfc8291Aes128GcmEncryptor(RANDOM),
                 // Signing needs a PKCS#8 EC key, which WebPushCryptoTest covers; the suites here
                 // are about transport and evidence semantics.
                 (endpoint, signingKey, publicKey) -> "vapid t=stub-token, k=" + publicKey,
@@ -240,7 +244,7 @@ public final class ContractAdapters {
       generator.initialize(new ECGenParameterSpec("secp256r1"));
       KeyPair pair = generator.generateKeyPair();
       byte[] authSecret = new byte[16];
-      new SecureRandom().nextBytes(authSecret);
+      RANDOM.nextBytes(authSecret);
       return new WebPushSubscriptionValue(
           URI.create(harness.baseUri() + "/push/subscription-1"),
           Rfc8291Aes128GcmEncryptor.encodePoint((ECPublicKey) pair.getPublic()),