docs: add Phylax Credible Layer developer docs

[airope]

Summary

Adds documentation for Phylax Systems' Credible Layer to the security tools section.

Changes

• docs/network/build/tools/security/phylax.mdx: New page covering:
  • What the Credible Layer is and how it works
  • Key features (pre-execution prevention, no contract changes, zero false positives)
  • Getting started links to Phylax documentation
  • Community and support resources

Closes #1190

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Note

Low Risk
Low risk: documentation-only addition with no runtime or API changes; main risk is incorrect/outdated external links or product claims.

Overview
Adds a new docs page docs/network/build/tools/security/phylax.mdx describing Phylax Systems’ Credible Layer (assertion-based, pre-execution transaction blocking) and summarizing its key features.

Includes curated Get started links (quickstart, architecture, assertions book) plus community/resource links (website, GitHub, Telegram, X).

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Project	Deployment	Actions	Updated (UTC)
doc-linea	Ready	Preview, Comment	Apr 27, 2026 3:14pm

[Othryades]

Hi @airope, thanks for opening this PR!
We already have a more detailed Linea guide for writing and deploying assertions, so I think the best value for this PR is as a short discoverability page under Tools > Security. Could you please revise it to:

Link clearly to our existing Linea assertions guide.
Keep the page brief and neutral, focused on what developers can use Phylax for.
Remove or soften absolute claims like “zero false positives.”
Add a description field to the frontmatter.
With those changes, this can complement the existing guide instead of duplicating it.