fix(deploy): Checkpoints — preserve STOPPED history, fix filter + placement

- Backend: rename deleteTerminalByAppAndEnvironment → deleteFailedByAppAndEnvironment.
  STOPPED rows were being wiped on every redeploy, so Checkpoints was always empty.
  Now only FAILED rows are pruned; STOPPED deployments are retained as restorable
  checkpoints (they still carry deployed_config_snapshot from their RUNNING window).
- UI filter: any deployment with a snapshot is a checkpoint (was RUNNING|DEGRADED only,
  which excluded the main case — the previous blue/green deployment now in STOPPED).
- UI placement: Checkpoints disclosure now renders inside IdentitySection, matching
  the design spec.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

cameleer-server-app/src/main/java/com/cameleer/server/app/storage/PostgresDeploymentRepository.java

@@ -126,8 +126,8 @@ public class PostgresDeploymentRepository implements DeploymentRepository {
     }
 
     @Override
-    public void deleteTerminalByAppAndEnvironment(UUID appId, UUID environmentId) {
-        jdbc.update("DELETE FROM deployments WHERE app_id = ? AND environment_id = ? AND status IN ('STOPPED', 'FAILED')",
+    public void deleteFailedByAppAndEnvironment(UUID appId, UUID environmentId) {
+        jdbc.update("DELETE FROM deployments WHERE app_id = ? AND environment_id = ? AND status = 'FAILED'",
                 appId, environmentId);
     }
 

cameleer-server-app/src/test/java/com/cameleer/server/app/storage/PostgresDeploymentRepositoryIT.java

@@ -87,6 +87,27 @@ class PostgresDeploymentRepositoryIT extends AbstractPostgresIT {
         assertThat(loaded.deployedConfigSnapshot()).isNull();
     }
 
+    @Test
+    void deleteFailedByAppAndEnvironment_keepsStoppedAndActive() {
+        // given: one STOPPED (checkpoint), one FAILED, one RUNNING
+        UUID stoppedId = repository.create(appId, appVersionId, envId, "stopped");
+        repository.updateStatus(stoppedId, com.cameleer.server.core.runtime.DeploymentStatus.STOPPED, null, null);
+
+        UUID failedId = repository.create(appId, appVersionId, envId, "failed");
+        repository.updateStatus(failedId, com.cameleer.server.core.runtime.DeploymentStatus.FAILED, null, "boom");
+
+        UUID runningId = repository.create(appId, appVersionId, envId, "running");
+        repository.updateStatus(runningId, com.cameleer.server.core.runtime.DeploymentStatus.RUNNING, "c1", null);
+
+        // when
+        repository.deleteFailedByAppAndEnvironment(appId, envId);
+
+        // then: STOPPED and RUNNING survive; FAILED is gone
+        assertThat(repository.findById(stoppedId)).isPresent();
+        assertThat(repository.findById(runningId)).isPresent();
+        assertThat(repository.findById(failedId)).isEmpty();
+    }
+
     @Test
     void deployedConfigSnapshot_canBeClearedToNull() {
         UUID jarVersionId = UUID.randomUUID();