adds clean copy of dual-vm-stack.md page and updated LLMs files

[dawnkelly09]

📝 Description

Provide a clear and concise description of your changes.

I made a mess out of attempting to clear merge conflicts for #1028 and accidentally merged in changes from master rather than staging. This PR adds the new documentation page Nico added in his PR and updates the LLMs files with the added content. This PR should be merged INSTEAD of #1028, which can then be closed.

[Copilot]

Pull Request Overview

This PR updates the documentation for Polkadot's smart contract virtual machine architecture by replacing the previous "PolkaVM Design" page with a new "Dual Virtual Machine Stack" page. The changes reflect Polkadot's dual-VM approach, introducing REVM (Rust Ethereum Virtual Machine) for EVM compatibility alongside the existing PolkaVM content.

• Restructured content to emphasize both REVM and PolkaVM options
• Updated page title, description, and section headings
• Removed compilation process details and mermaid diagrams showing VM architecture comparison
• Added migration guidance for choosing between REVM and PolkaVM

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
smart-contracts/for-eth-devs/dual-vm-stack.md	Complete rewrite introducing dual-VM architecture with REVM and PolkaVM
llms.txt	Updated page title and description references
llms-full.jsonl	Updated metadata, content, and structure for the new page
.ai/site-index.json	Updated last modified timestamps across multiple entries
.ai/pages/smart-contracts-for-eth-devs-dual-vm-stack.md	AI-generated page version with same content updates
.ai/categories/*.md	Updated category files with new page content

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[eshaben]

@dawnkelly09 merge conflicts 🙃