feat(ci): Add uv and Python package sync to copilot-setup-steps

[WilliamBerryiii]

Summary

The Copilot Coding Agent runs in a cloud-based GitHub Actions environment configured by copilot-setup-steps.yml. This workflow pre-installs tools to match devcontainer capabilities. It currently lacks uv installation and Python dependency resolution, meaning the Coding Agent cannot run Python linting or testing commands.

Context

Issue #388 (closed) established the copilot-setup-steps.yml pattern for tool parity between local and agent environments. Issue #514 (closed, v3.0.0) addressed specific parity gaps between the devcontainer and copilot-setup-steps. The copilot-instructions.md documents an explicit Environment Synchronization section stating that when adding tools to either environment, both should be evaluated for the same change.

With PR #868 introducing Python skills and #887 adding uv to the devcontainer, this workflow must be updated to maintain parity. The Copilot Agent environment already has Python 3.11 available (documented in copilot-instructions.md), but needs uv for package management and dependency resolution.

Changes Required

File	Change
.github/workflows/copilot-setup-steps.yml	Add uv installation step
.github/workflows/copilot-setup-steps.yml	Add uv sync step for Python dependency resolution using dynamic discovery
.github/copilot-instructions.md	Update Pre-installed Tools section to document uv availability

The uv installation should use a pinned version and verified download method consistent with the devcontainer approach (#887). The uv sync step should discover and iterate over all pyproject.toml files under .github/skills/ using the same pattern as the devcontainer:

find .github/skills -name pyproject.toml -execdir uv sync \;

This ensures parity with the devcontainer (#887) and automatically resolves dependencies for new Python skills without workflow modifications.

Acceptance Criteria

• uv is installed and available on PATH in the Copilot Agent environment
• uv sync resolves Python dependencies for all pyproject.toml files found under .github/skills/
• npm run lint:py and npm run test:py work in the Copilot Agent environment
• copilot-instructions.md Pre-installed Tools section lists uv
• Environment Synchronization section reflects Python tooling additions
• Adding a new Python skill with pyproject.toml is automatically resolved without workflow changes
• The workflow continues to complete within reasonable time bounds

Dependencies

• Should be coordinated with feat(devcontainer): Add Python development extensions and uv package manager #887 (devcontainer changes) to maintain parity
• Python npm scripts (feat(scripts): Add npm run scripts for Python linting and testing #886) will consume the tools installed here

Related

• PR feat(skills): add PowerPoint automation skill with YAML-driven deck generation #868 — PowerPoint automation skill (first Python skill)
• feat(devcontainer): Add Python development extensions and uv package manager #887 — DevContainer Python extensions and uv installation
• feat(scripts): Add npm run scripts for Python linting and testing #886 — npm scripts for Python linting and testing
• fix(devcontainer): resolve tool parity gaps between devcontainer and copilot-setup-steps #514 — Prior devcontainer/copilot-setup parity work (closed)
• [Issue]: Ensure Tool Parity Between DevContainer, Custom Agents, and GitHub Copilot Coding Agent #388 — Established copilot-setup-steps pattern (closed)