feat: Add .result for path-configured trees.

[vic]

No description provided.

[Copilot]

Pull Request Overview

This PR introduces a .result attribute to trees configured via paths, updates tests to use this new property, and refreshes documentation to show its usage.

• Add result field to default.nix for returning the final leaf list without extra paths
• Update checkmate.nix tests to replace leafs [] with .leafs.result and add an identity test
• Revise README.md to document pre-configured subtree sharing and show .result in examples

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
default.nix	Added result = (self f) [ ]; and a brief comment
checkmate.nix	Swapped .leafs [] calls for .leafs.result, new test
README.md	Updated pattern links, renamed section, added .result example

Comments suppressed due to low confidence (2)

default.nix:86

• [nitpick] The comment is a bit unclear. Consider clarifying what ‘empty’ refers to, e.g., “Returns the configured tree’s leaf list with no additional paths.”

          # Applies empty (for already path-configured trees)

README.md:286

• [nitpick] Consider adding a short remark before this example explaining that .result extracts the final filtered leaf list from the configured tree, for clarity to new users.

    (lib.pipe root [(on "vim") (off "emacs") (i: i.result)])