feat(clickhouse): wire ClickHouseExecutionStore as active ExecutionStore

Add cameleer.storage.executions feature flag (default: clickhouse).
PostgresExecutionStore activates only when explicitly set to postgres.
Add by-seq snapshot endpoint for iteration-aware processor lookup.

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

cameleer3-server-app/src/main/java/com/cameleer3/server/app/config/StorageBeanConfig.java

@@ -6,6 +6,7 @@ import com.cameleer3.server.app.storage.ClickHouseDiagramStore;
 import com.cameleer3.server.app.storage.ClickHouseMetricsQueryStore;
 import com.cameleer3.server.app.storage.ClickHouseMetricsStore;
 import com.cameleer3.server.app.storage.ClickHouseStatsStore;
+import com.cameleer3.server.app.storage.PostgresExecutionStore;
 import com.cameleer3.server.app.storage.PostgresMetricsQueryStore;
 import com.cameleer3.server.app.storage.PostgresMetricsStore;
 import com.cameleer3.server.core.admin.AuditRepository;
@@ -96,6 +97,18 @@ public class StorageBeanConfig {
         return new ClickHouseExecutionStore(clickHouseJdbc);
     }
 
+    @Bean
+    @ConditionalOnProperty(name = "cameleer.storage.executions", havingValue = "clickhouse", matchIfMissing = true)
+    public ExecutionStore executionStoreClickHouse(ClickHouseExecutionStore chStore) {
+        return chStore;  // Same instance, also exposed as ExecutionStore
+    }
+
+    @Bean
+    @ConditionalOnProperty(name = "cameleer.storage.executions", havingValue = "postgres")
+    public ExecutionStore executionStorePostgres(JdbcTemplate jdbc) {
+        return new PostgresExecutionStore(jdbc);
+    }
+
     @Bean
     @ConditionalOnProperty(name = "clickhouse.enabled", havingValue = "true")
     public ChunkAccumulator chunkAccumulator(

cameleer3-server-app/src/main/java/com/cameleer3/server/app/controller/DetailController.java

@@ -81,4 +81,16 @@ public class DetailController {
             .map(ResponseEntity::ok)
             .orElse(ResponseEntity.notFound().build());
     }
+
+    @GetMapping("/{executionId}/processors/by-seq/{seq}/snapshot")
+    @Operation(summary = "Get exchange snapshot for a processor by seq number")
+    @ApiResponse(responseCode = "200", description = "Snapshot data")
+    @ApiResponse(responseCode = "404", description = "Snapshot not found")
+    public ResponseEntity<Map<String, String>> processorSnapshotBySeq(
+            @PathVariable String executionId,
+            @PathVariable int seq) {
+        return detailService.getProcessorSnapshotBySeq(executionId, seq)
+                .map(ResponseEntity::ok)
+                .orElse(ResponseEntity.notFound().build());
+    }
 }

cameleer3-server-app/src/main/java/com/cameleer3/server/app/storage/PostgresExecutionStore.java

@@ -3,7 +3,6 @@ package com.cameleer3.server.app.storage;
 import com.cameleer3.server.core.storage.ExecutionStore;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
-import org.springframework.stereotype.Repository;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
@@ -12,7 +11,6 @@ import java.time.Instant;
 import java.util.List;
 import java.util.Optional;
 
-@Repository
 public class PostgresExecutionStore implements ExecutionStore {
 
     private final JdbcTemplate jdbc;

cameleer3-server-app/src/main/resources/application.yml

@@ -55,6 +55,7 @@ cameleer:
     diagrams: ${CAMELEER_STORAGE_DIAGRAMS:clickhouse}
     events: ${CAMELEER_STORAGE_EVENTS:clickhouse}
     logs: ${CAMELEER_STORAGE_LOGS:clickhouse}
+    executions: ${CAMELEER_STORAGE_EXECUTIONS:clickhouse}
 
 security:
   access-token-expiry-ms: 3600000

deploy/base/server.yaml

@@ -101,6 +101,8 @@ spec:
               value: "clickhouse"
             - name: CAMELEER_STORAGE_LOGS
               value: "clickhouse"
+            - name: CAMELEER_STORAGE_EXECUTIONS
+              value: "clickhouse"
 
           resources:
             requests: