v0.4.0

AnimeLibrarian 0.4.0 is a focused rewrite of the CLI around a smaller, linear
runtime with safer filesystem boundaries and a cleaner terminal experience.

Highlights

• Polished Rich move-plan tables plus clean plain-text and JSON Lines output.
• One review and confirmation flow, with overwrite prompts defaulting to no.
• Strict validation of AI-suggested paths, extensions, duplicates, symlinks,
  Unicode/case collisions, and late filesystem replacements.
• Socket-free Dify tests, consolidated CI, and a substantially smaller runtime.
• Added .m4v, .mpg, .mpeg, and .idx media support.

Upgrade notes

• Source discovery is non-recursive and ignores symlinks.
• The legacy provider, protocol, output-writer, Rich-wrapper, and mock-server
  layers were removed.
• The bundled Dify prompts now consistently emit the result field expected by
  the CLI.

See CHANGELOG.md for the complete change list.