Enhance README with architecture flow and model details

[etherbiswas]

Description

Problem or Issue being addressed

The current documentation lacked a detailed breakdown of structure for code, making it hard to make changes for new contributors/devs.

Solution

Modified README.md -- Now includes detailed breakdown using Mermaid flowcharts. Covers layer map, boot sequence, main user flow.

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This pull request is categorized as a:

• Documentation

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Checklist

I ran pytest locally

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I included screenshots of any new or modified screens

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I added or updated tests

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I tested this PR hands-on on the following platform(s):

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I have reviewed these notes:

• Keep your changes limited in scope.
• If you uncover other issues or improvements along the way, ideally submit those as a separate PR.
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• I understand

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