[TypeSpec Authoring] Support complex resource hierarchy cases

## Overview

Extend the `azure-typespec-author` skill to handle complex resource hierarchy scenarios beyond simple top-level and single-level child resources. This includes deeply nested resources, multiple parent types, and mixed hierarchies common in real ARM services.

example PR: https://github.com/Azure/azure-rest-api-specs/pull/41694

## Problem

The current skill supports basic resource hierarchy:
- Top-level tracked resources
- Single-level child (proxy) resources with one parent

Real-world ARM services often have more complex hierarchies that the skill does not yet handle correctly, leading to incorrect TypeSpec generation or requiring manual intervention.

## Known Complex Hierarchy Cases

- [ ] Multi-level nested resources (grandchild and deeper)
- [ ] Resources shared across multiple parent scopes

## Parent Issue

Part of #15331