#2574: fix(diagnostics-otel): update to @opentelemetry/resources v2.x API

## Summary The `diagnostics-otel` plugin fails to load with: ``` TypeError: _resources.Resource is not a constructor ``` ## Root Cause The `@opentelemetry/resources` package v2.x removed the `Resource` class export. The new API uses `resourceFromAttributes()` function instead. From the package's index.js (v2.5.0): ```js export { resourceFromAttributes, defaultResource, emptyResource } from './ResourceImpl'; ``` Note: No `Resource` class is exported. ## Fix - Replace `import { Resource }` with `import { resourceFromAttributes }` - Replace `new Resource({...})` with `resourceFromAttributes({...})` ## Testing Tested locally on macOS with Node 22.22.0 — plugin now loads successfully and exports telemetry to Honeycomb. --- Found while debugging with Clawdbot 🤖 <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> Updates the `diagnostics-otel` plugin to match `@opentelemetry/resources` v2.x by switching from the removed `Resource` class to the new `resourceFromAttributes()` API, fixing the runtime `TypeError: Resource is not a constructor` when the plugin starts. Change is localized to `extensions/diagnostics-otel/src/service.ts`, where the constructed resource passed into `NodeSDK`/`LoggerProvider` now uses `resourceFromAttributes({ [SemanticResourceAttributes.SERVICE_NAME]: serviceName })`. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk. - The change is a straightforward API migration (import + constructor → function call) confined to a single location, and it directly addresses the reported runtime failure. No behavioral changes beyond resource construction were introduced. - No files require special attention <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->