Add specialized Copilot agent team for Python/wxPython desktop accessibility

[Nael-Sayegh]

Summary

This issue tracks the introduction of a dedicated GitHub Copilot agent team for BasiliskLLM, focused on the Python/wxPython desktop accessibility stack.

Resolved by #1097.

Motivation

The project spans several distinct technical domains — Python packaging and testing, wxPython GUI development, platform accessibility APIs, screen reader testing, and accessibility tooling architecture. Using a single general-purpose Copilot assistant for all of these leads to shallow, unfocused advice and frequent context-switching overhead for contributors.

A team of specialized agents with explicit routing and handoff logic improves the quality and precision of AI-assisted development across all these areas.

What was done

• Added agents with six specialized agent definitions and a shared instructions file.
• Defined developer-hub as the default entry point, routing tasks to the appropriate specialist.
• Each agent carries curated authoritative references, required tool usage rules, and bidirectional handoff definitions.
• Added AGENTS.md as a human-readable routing guide for contributors.

Agents introduced

Agent	Domain
developer-hub	Lead — triage and routing
python-specialist	Python language, testing, packaging
wxpython-specialist	wxPython GUI and threading
desktop-a11y-specialist	Platform accessibility APIs
desktop-a11y-testing-coach	Screen reader and accessibility testing
a11y-tool-builder	Accessibility scanning tool architecture