Microsoft.ApplicationInsights.WorkerService 3.0.0 incompatible with Azure Functions Worker - Breaking change

## Summary

Microsoft.ApplicationInsights.WorkerService 3.0.0 introduces breaking changes that cause runtime failures when used with Azure Functions isolated worker model.

## Error

```
TypeLoadException: Could not load type 'Microsoft.ApplicationInsights.Extensibility.ITelemetryInitializer' from assembly 'Microsoft.ApplicationInsights, Version=3.0.0.1'
```

## Root Cause

Version 3.0.0 migrated to OpenTelemetry with breaking changes to `ITelemetryInitializer` and other extensibility points, which are incompatible with the current `Microsoft.Azure.Functions.Worker.ApplicationInsights` telemetry integration.

## Environment

- **Azure Functions Worker**: 2.51.0
- **Functions Worker ApplicationInsights**: 2.50.0
- **.NET**: 10.0
- **ApplicationInsights.WorkerService**: 3.0.0 (broken) / 2.22.0 (works)

## Steps to Reproduce

1. Create a new Azure Functions isolated worker project targeting .NET 10
2. Add the latest `Microsoft.ApplicationInsights.WorkerService` (3.0.0)
3. Add `Microsoft.Azure.Functions.Worker.ApplicationInsights` (2.50.0)
4. Run `func start`
5. Observe `TypeLoadException`

## Workaround

Use Microsoft.ApplicationInsights.WorkerService version **2.22.0** (latest stable 2.x) instead of 3.x:

```xml

```

## Impact

Projects upgrading to .NET 10 (or any supported .NET version) may inadvertently upgrade to ApplicationInsights 3.x and encounter runtime failures. This is a common scenario as developers typically update all NuGet packages to latest stable versions.

## Recommendation

1. **Short-term**: Document this compatibility constraint in the package README and release notes
2. **Long-term**: Update `Microsoft.Azure.Functions.Worker.ApplicationInsights` to support ApplicationInsights 3.x SDK with OpenTelemetry

## Related

- **Discovery context**: [Azure-Samples/functions-quickstart-dotnet-azd#26](https://github.com/Azure-Samples/functions-quickstart-dotnet-azd/pull/26) - .NET 10 upgrade PR where this was discovered