feat(cli): add adk graph visual inspector, topology parser and debugger

[yuvaraj-97]

Closes #6817

Summary

This PR implements (Visual Agent Inspector, Bi-directional Code Generator, & Live Debugger) as proposed in issue #6817.

Features Included

1. AST Topology Parser & Inspector (): Renders dynamic/static agent delegation graph structures (SequentialAgent, ParallelAgent, LoopAgent, tools, memory).
2. Bi-directional Code Editor: Allows split-screen code and visual topology editing.
3. Live Execution Visualizer: Real-time active-node highlighting during runner execution.

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