fix(core): Resolve TypeScript strict mode and ES client API compatibility issues for v3.0.0

- Fix ES client v8+ API: use document/doc instead of body for index/update operations
- Add type assertions (as any) for ES client ILM, template, and search APIs
- Fix strict null checks with proper undefined handling (nullish coalescing)
- Fix MetricsCollector interface to match required method signatures
- Fix Logger.error signature compatibility in plugins
- Resolve TermsQuery type index signature conflict
- Remove sourceMap from tsconfig (handled by tsbuild with inlineSourceMap)

ts/domain/documents/document-session.ts

@@ -1,10 +1,10 @@
 import type { Client as ElasticClient } from '@elastic/elasticsearch';
-import {
+import type {
   BatchOperation,
   BatchResult,
-  DocumentOperation,
   SessionConfig,
 } from './types.js';
+import { DocumentOperation } from './types.js';
 import { Logger } from '../../core/observability/logger.js';
 import { BulkOperationError } from '../../core/errors/elasticsearch-error.js';
 
@@ -237,16 +237,20 @@ export class DocumentSession<T = unknown> {
         const item = response.items[i];
         const operation = this.operations[i];
 
-        const action = Object.keys(item)[0];
-        const result = item[action as keyof typeof item] as any;
+        if (!item || !operation) continue;
 
-        if (result.error) {
+        const action = Object.keys(item)[0];
+        if (!action) continue;
+        const result = item[action as keyof typeof item] as Record<string, unknown> | undefined;
+
+        if (result?.error) {
           failed++;
+          const errorInfo = result.error as { reason?: string } | string;
           errors.push({
             documentId: operation.documentId,
             operation: operation.operation,
-            error: result.error.reason || result.error,
-            statusCode: result.status,
+            error: typeof errorInfo === 'string' ? errorInfo : (errorInfo.reason ?? 'Unknown error'),
+            statusCode: result.status as number,
           });
         } else {
           successful++;
@@ -276,7 +280,7 @@ export class DocumentSession<T = unknown> {
           'All bulk operations failed',
           successful,
           failed,
-          errors
+          errors.map(e => ({ documentId: e.documentId, error: e.error, status: e.statusCode }))
         );
       }
     }
@@ -304,13 +308,11 @@ export class DocumentSession<T = unknown> {
 
       await this.client.deleteByQuery({
         index: this.index,
-        body: {
-          query: {
-            bool: {
-              must_not: {
-                ids: {
-                  values: seenIds,
-                },
+        query: {
+          bool: {
+            must_not: {
+              ids: {
+                values: seenIds,
               },
             },
           },
@@ -320,7 +322,7 @@ export class DocumentSession<T = unknown> {
 
       this.logger.debug('Stale documents cleaned up', { index: this.index });
     } catch (error) {
-      this.logger.warn('Failed to cleanup stale documents', undefined, {
+      this.logger.warn('Failed to cleanup stale documents', {
         index: this.index,
         error: (error as Error).message,
       });