feat: update support for codex cli

[35C4n0r]

• support codex cli v0.20.0

[35C4n0r]

@hugodutka @matifali PR ready for review

[Copilot]

Pull Request Overview

This PR updates the msgfmt library to support Codex CLI v0.20.0 by updating test data and message formatting logic to match the new interface format.

• Updates test data files to reflect new Codex CLI output format with simplified welcome message and different status indicators
• Simplifies the Codex message formatting function by removing legacy message box handling and implementing new input box removal logic
• Removes a specific term height limitation for Codex that is no longer needed

Reviewed Changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
lib/msgfmt/testdata/format/codex/*/user.txt	Updates user input test cases with new question formats
lib/msgfmt/testdata/format/codex/*/msg.txt	Updates raw message format to match new Codex CLI v0.20.0 output
lib/msgfmt/testdata/format/codex/*/expected.txt	Updates expected formatting results for new Codex interface
lib/msgfmt/msgfmt.go	Simplifies formatCodexMessage function by removing legacy message box handling
lib/msgfmt/message_box.go	Refactors removeCodexMessageBox to removeCodexInputBox with updated logic for new format
cmd/server/server.go	Removes Codex-specific terminal height limitation workaround

[35C4n0r]

@hugodutka resolved all.