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/examples/logging/logging-example.ts

@@ -17,7 +17,6 @@ import {
   addDynamicTags,
   chainEnrichers,
 } from '../../index.js';
-import type { LogEntry } from '../../index.js';
 
 async function main() {
   console.log('=== Logging API Example ===\n');