refactor(search): drop dead SearchIndexer subsystem

After the ExecutionController removal (0f635576), SearchIndexer
subscribed to ExecutionUpdatedEvent but nothing publishes that event.
Every SearchIndexerStats metric returned always-zero, and the admin
/api/v1/admin/clickhouse/pipeline endpoint that surfaced those stats
carried no signal.

Backend removed:
- core: SearchIndexer, SearchIndexerStats, ExecutionUpdatedEvent
- app: IndexerPipelineResponse DTO, /pipeline endpoint on
  ClickHouseAdminController (field + ctor param)
- StorageBeanConfig.searchIndexer bean

UI removed:
- IndexerPipeline type + useIndexerPipeline hook in
  api/queries/admin/clickhouse.ts
- Indexer Pipeline card in ClickHouseAdminPage.tsx (plus ProgressBar
  import and pipeline* CSS classes)

OpenAPI schema.d.ts + openapi.json regenerated (stale /pipeline path
and IndexerPipelineResponse schema removed).

SearchIndex interface + ClickHouseSearchIndex impl kept — those are
live and used by SearchService + ExchangeMatchEvaluator.

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

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

@@ -16,7 +16,6 @@ import com.cameleer.server.core.agent.AgentEventRepository;
 import com.cameleer.server.core.agent.AgentInfo;
 import com.cameleer.server.core.agent.AgentRegistryService;
 import com.cameleer.server.core.detail.DetailService;
-import com.cameleer.server.core.indexing.SearchIndexer;
 import com.cameleer.server.app.ingestion.ExecutionFlushScheduler;
 import com.cameleer.server.app.search.ClickHouseSearchIndex;
 import com.cameleer.server.app.storage.ClickHouseExecutionStore;
@@ -43,13 +42,6 @@ public class StorageBeanConfig {
         return new DetailService(executionStore);
     }
 
-    @Bean(destroyMethod = "shutdown")
-    public SearchIndexer searchIndexer(ExecutionStore executionStore, SearchIndex searchIndex,
-                                        @Value("${cameleer.server.indexer.debouncems:2000}") long debounceMs,
-                                        @Value("${cameleer.server.indexer.queuesize:10000}") int queueSize) {
-        return new SearchIndexer(executionStore, searchIndex, debounceMs, queueSize);
-    }
-
     @Bean
     public AuditService auditService(AuditRepository auditRepository) {
         return new AuditService(auditRepository);

cameleer-server-app/src/main/java/com/cameleer/server/app/controller/ClickHouseAdminController.java

@@ -4,8 +4,6 @@ import com.cameleer.server.app.dto.ClickHousePerformanceResponse;
 import com.cameleer.server.app.dto.ClickHouseQueryInfo;
 import com.cameleer.server.app.dto.ClickHouseStatusResponse;
 import com.cameleer.server.app.dto.ClickHouseTableInfo;
-import com.cameleer.server.app.dto.IndexerPipelineResponse;
-import com.cameleer.server.core.indexing.SearchIndexerStats;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import org.springframework.beans.factory.annotation.Qualifier;
@@ -31,15 +29,12 @@ import java.util.List;
 public class ClickHouseAdminController {
 
     private final JdbcTemplate clickHouseJdbc;
-    private final SearchIndexerStats indexerStats;
     private final String clickHouseUrl;
 
     public ClickHouseAdminController(
             @Qualifier("clickHouseJdbcTemplate") JdbcTemplate clickHouseJdbc,
-            SearchIndexerStats indexerStats,
             @Value("${cameleer.server.clickhouse.url:}") String clickHouseUrl) {
         this.clickHouseJdbc = clickHouseJdbc;
-        this.indexerStats = indexerStats;
         this.clickHouseUrl = clickHouseUrl;
     }
 
@@ -157,16 +152,4 @@ public class ClickHouseAdminController {
         }
     }
 
-    @GetMapping("/pipeline")
-    @Operation(summary = "Search indexer pipeline statistics")
-    public IndexerPipelineResponse getPipeline() {
-        return new IndexerPipelineResponse(
-                indexerStats.getQueueDepth(),
-                indexerStats.getMaxQueueSize(),
-                indexerStats.getFailedCount(),
-                indexerStats.getIndexedCount(),
-                indexerStats.getDebounceMs(),
-                indexerStats.getIndexingRate(),
-                indexerStats.getLastIndexedAt());
-    }
 }

cameleer-server-app/src/main/java/com/cameleer/server/app/dto/IndexerPipelineResponse.java

@@ -1,16 +0,0 @@
-package com.cameleer.server.app.dto;
-
-import io.swagger.v3.oas.annotations.media.Schema;
-
-import java.time.Instant;
-
-@Schema(description = "Search indexer pipeline statistics")
-public record IndexerPipelineResponse(
-        int queueDepth,
-        int maxQueueSize,
-        long failedCount,
-        long indexedCount,
-        long debounceMs,
-        double indexingRate,
-        Instant lastIndexedAt
-) {}