fix(issue)!: make subject mandatory and optional content

BREAKING CHANGE: When the editor contains only one line, it is now
treated as the subject instead of being used as the issue content.

Signed-off-by: Awiteb <a@4rs.nl>

CHANGELOG.md

@@ -5,6 +5,20 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Added
+
+- New command `repo state` - by Awiteb
+
+### Breaking Change
+
+- Make subject mandatory and optional content - by Awiteb
+
+### Fixed
+
+- Check the nip07 signer in `CliOptions::ensure_signer` - by Awiteb
+
 ## [0.4.0] - 2025-08-08
 
 ### Added