fix: hide changelog banner when messages are present

Fix issue where changelog banner remained visible after messages were sent.
Apply the same logic as beta badge to hide when messages exist.

Changes:
- Add messages-changed event listener to ChangelogBanner
- Hide banner when hasMessages is true
- Maintain consistency with BetaBadge behavior

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

docs: Add v1.0.0 beta testing information to README

Added comprehensive beta testing section including:
- Beta environment information (beta.morphic.sh)
- v1.0.0 branch explanation and merge conditions
- Branch selection guidance for users
- Feedback methods (GitHub Issues and in-app feedback button)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Merge pull request #707 from miurla/chore/changelog-beta7

Update changelog for v1.0.0 Beta.7

Release v1.0.0-beta.6

Release v0.4.6

Release v1.0.0-beta.5

- New Research Process UI with grouped sections
- Improved Thoughts display for better readability
- Enhanced TODO tracking with progress visualization

Merge pull request #679 from miurla/fix/message-actions-visibility

fix: avoid invisible action row in text parts

Merge pull request #655 from miurla/feature/animated-loading-logo

feat: add animated loading logo with eye movement

Merge pull request #624 from miurla/tailwind-v4-upgrade

feat: upgrade to Tailwind CSS v4.1.11 with CSS-based configuration

Merge pull request #589 from miurla/feat/dynamic-tools-support

feat: add support for AI SDK v5 dynamic tools