Proposal: Move diff, bundler, and optimizer into CLI

As part of the 2026 community goals (more details here: https://github.com/asyncapi/community/issues/3495), we conducted an audit of all repositories. The summary of the findings can be found here: https://github.com/asyncapi/community/issues/3495#issuecomment-4681625773.

As suggested by @deberg, we are proposing to move the `diff`, `bundler`, and `optimizer` repositories to the CLI repository.

Reference to the conversation:
- https://asyncapi.slack.com/archives/C34F2JV0U/p1774973085382029?thread_ts=1774874525.585229&cid=C34F2JV0U
- https://github.com/asyncapi/community/issues/3495

I am opening this issue to gather feedback and approval from the code owners of this repository regarding the proposal to move diff, bundler, and optimizer repository to CLI.

Tagging all code owners for their feedback and approval.
@Souvikns @Amzani @Shurtu-gal @AayushSaini101

Start by reading the linked community issue and its audit summary, then review the referenced Slack conversation. This issue is seeking code-owner feedback and approval for moving the diff, bundler, and optimizer repositories into the CLI repository. It is done when the proposal receives a clear decision from the relevant code owners.

Written by the indexing model from the issue text.