fix: resolve duplicate ExecutionStore bean conflict

ClickHouseExecutionStore implements ExecutionStore, so the concrete bean
already satisfies the interface — remove redundant wrapper bean. Align
ChunkAccumulator and ExecutionFlushScheduler conditions to
cameleer.storage.executions flag.

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

@@ -88,19 +88,13 @@ public class StorageBeanConfig {
         return new PostgresMetricsQueryStore(jdbc);
     }
 
-    // ── ClickHouse Execution Store ──────────────────────────────────────
+    // ── Execution Store ──────────────────────────────────────────────────
-
-    @Bean
-    @ConditionalOnProperty(name = "clickhouse.enabled", havingValue = "true")
-    public ClickHouseExecutionStore clickHouseExecutionStore(
-            @Qualifier("clickHouseJdbcTemplate") JdbcTemplate clickHouseJdbc) {
-        return new ClickHouseExecutionStore(clickHouseJdbc);
-    }
 
     @Bean
     @ConditionalOnProperty(name = "cameleer.storage.executions", havingValue = "clickhouse", matchIfMissing = true)
-    public ExecutionStore executionStoreClickHouse(ClickHouseExecutionStore chStore) {
+    public ClickHouseExecutionStore clickHouseExecutionStore(
-        return chStore;  // Same instance, also exposed as ExecutionStore
+            @Qualifier("clickHouseJdbcTemplate") JdbcTemplate clickHouseJdbc) {
+        return new ClickHouseExecutionStore(clickHouseJdbc);
     }
 
     @Bean
@@ -110,7 +104,7 @@ public class StorageBeanConfig {
     }
 
     @Bean
-    @ConditionalOnProperty(name = "clickhouse.enabled", havingValue = "true")
+    @ConditionalOnProperty(name = "cameleer.storage.executions", havingValue = "clickhouse", matchIfMissing = true)
     public ChunkAccumulator chunkAccumulator(
             WriteBuffer<MergedExecution> executionBuffer,
             WriteBuffer<ChunkAccumulator.ProcessorBatch> processorBatchBuffer) {
@@ -121,7 +115,7 @@ public class StorageBeanConfig {
     }
 
     @Bean
-    @ConditionalOnProperty(name = "clickhouse.enabled", havingValue = "true")
+    @ConditionalOnProperty(name = "cameleer.storage.executions", havingValue = "clickhouse", matchIfMissing = true)
     public ExecutionFlushScheduler executionFlushScheduler(
             WriteBuffer<MergedExecution> executionBuffer,
             WriteBuffer<ChunkAccumulator.ProcessorBatch> processorBatchBuffer,