feat: enhance create_patch to skip existing identical patches and apply incremental changes

[zelosleone]

WIP

[Copilot]

Pull Request Overview

Enhance create_patch to skip applying patches when there are no changes and generate incremental suffix-only diffs on top of existing patches.

• Introduce a temporary copy of the original source to apply existing patches and compute only new changes.
• Emit full diffs when no prior patches exist, and suffix-only diffs otherwise.
• Persist updated patch lists back to .source_info.json.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/source/create_patch.rs	Incremental patch logic, temp directory handling, and updating source info
src/recipe/parser/source.rs	Made UrlSource fields public to allow push of newly created patches

Comments suppressed due to low confidence (3)

src/source/create_patch.rs:83

• Add or update the doc comment for create_patch to describe the new incremental behavior and the conditions under which full vs. suffix-only diffs are generated.

    ];

src/source/create_patch.rs:175

• Include unit or integration tests that verify suffix-only diffs are correctly generated when existing patches are applied, as well as full diffs when none exist.

                        for entry in WalkDir::new(&target_dir)

src/recipe/parser/source.rs:390

• [nitpick] The field holds multiple URLs but is named url; consider renaming to urls for consistency with the urls() accessor.

    pub url: Vec<Url>,