[Copilot]

What

• Add four one-click clipboard actions to the ArcGIS Pro CLI ribbon:
  • selected layer datasource path
  • project home folder
  • APRX path
  • selected layer fields
• Wire new buttons into ProExporter/Config.daml with explicit labels/tooltips.
• Implement clipboard handlers in ProExporter/Buttons.cs, including TOC selection lookup and field serialization.

Why

• Common project and layer metadata currently requires digging through Properties/Contents or exporting context first.
• This shortens a frequent copy/paste workflow into a single ribbon click.

How to test

• Open an .aprx in ArcGIS Pro and verify the new ribbon buttons appear under the CLI tab.
• Select a feature layer in the Contents pane and confirm:
  • Copy Layer Path places the dataset path on the clipboard
  • Copy Layer Fields places tab-separated field metadata on the clipboard
• Confirm Copy Home Folder and Copy APRX Path copy the current project paths.

var selectedLayer = MapView.Active.GetSelectedLayers().First();
Clipboard.SetText(project.URI);

Notes / risks

• Field copy is limited to selected feature layers; non-feature selections return a user-facing message.
• Datasource path resolution is best-effort across feature and raster layers and may fall back to layer/data connection metadata for some source types.

• Fixes Add copy buttons to the ribbon #53