Polish remaining styling and UX details for revision flow

[pedrogaudencio]

Problem

The main revision flow in implemented in #154, but some styling, wording, and UI details are still missing or not fully aligned with the intended experience. A few elements remain too technical, inconsistent, or not yet adapted to the new flow.

Solution

Apply the remaining styling and UX adjustments needed to complete the feature. This includes:

• updating the WYSIWYG editor
• removing Git-related commands from the UI
• updating the copywriting
• using the subject name instead of the repository name
• address anchor link in individual commits - goes to /article/{user}/{subject}/commit/{hash} but there's no page to show this specific diff
• remove branch dropdown select (when editing CR title)
• remove "delete branch" option on merge (set always delete as default)
• remove "deleted branch" comment message (normally displayed after deleting a branch)