The copilot project target installed only skills and agents, dropping the
entire rules/ tree even though Copilot CLI and VS Code read path-specific
instructions from .github/instructions/**/*.instructions.md.
Plan each rules/**/*.md file into .github/instructions/ecc/ as an
.instructions.md file and add a copilot-rule-frontmatter transform that maps
the Claude-style `paths:` list onto Copilot's `applyTo:` glob list. Rules
without `paths:` become applyTo: "**", matching their always-on semantics in
Claude Code. rules/README.md documents the rule set and is not installed.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>