Remove add_directory() from ModuleWriter trait

[e-nomem]

In #2823 I considered the idea of removing add_directory() entirely from the ModuleWriter trait since it seemed error-prone to require the programmer to ensure it was called everywhere. I decided to make a PR for that as well to see what it would look like.

[Copilot]

Pull Request Overview

This PR refactors directory creation in the module writer system by removing the add_directory() method from the ModuleWriter trait and making it an implementation detail handled automatically by PathWriter when adding files.

• Removed the add_directory() method from the ModuleWriter trait interface
• Updated PathWriter to automatically create parent directories when adding files
• Simplified code by removing explicit directory creation calls throughout the codebase

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/module_writer.rs	Removed add_directory() from trait and all implementations; added automatic parent directory creation in PathWriter.add_bytes_with_permissions()
src/source_distribution.rs	Removed explicit add_directory() calls and simplified conditional logic to skip directories
src/build_context.rs	Removed unnecessary add_directory() call for libs directory
tests/common/metadata.rs	Removed add_directory() implementation from MockWriter and updated test expectations to exclude directory entries
Changelog.md	Added changelog entry documenting the refactoring

[messense]

Thanks!