docs: Add contexty plugin to ecosystem documentation

[obtuse-triangle]

Issue for this PR

Closes #

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

This PR adds the Contexty plugin to the official OpenCode EcoSystem documentation. Contexty is an OpenCode CLI extension specifically designed to solve the common issues of "Context Twisting" and "Architecture Collapse" when working with AI coding agents.

The documentation highlights Contexty's 5 core features:

• HSCMM: Provides 100% visualization and control over the AI's current context window, fundamentally preventing the "the AI forgot" excuse.
• AASM (Agent Supervision): Acts as an architecture sentinel. It inspects prompts before coding begins to proactively warn against anti-patterns like God Objects or Monolithic structures.
• TLS: Instantly extracts and summarizes the core errors or success states from thousands of lines of terminal logs in just a second.
• HSCMM+DCP: Automatically compresses context, allowing users to visually verify the compressed results through HSCMM.

Additionally, when integrated with VSCode Extension, Contexty provides intuitive visualizations as shown in the attached recording, while still remaining fully functional and seamlessly operable as a standalone CLI tool.

Plugin Repo: https://github.com/ttalkkak-lab/opencode-contexty

How did you verify your code works?

I verified that the markdown syntax is valid and renders correctly according to the repository's documentation standards.

Screenshots / recordings

a10.webm

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR