Inline confirmation dialogs, Slack improvements, and bug fixes

This update introduces inline confirmation dialogs that let you review actions before the agent executes them. The Slack integration gains more concise responses and usability improvements, along with several bug fixes.

The agent now pauses and asks for your confirmation before executing actions that modify content. A confirm/cancel dialog appears inline in the chat, giving you a chance to review what the agent is about to do before it proceeds. Unlike the existing approval step for bulk edits, this applies to individual actions as they happen.

• Slack - more concise responses: The Slack agent now gives shorter, more focused answers.
• Slack - display names in suggestions: Suggestion dropdowns in the Slack integration now show real names instead of IDs.

• Fixed a crash that could occur when switching between the proposed changes tab and Studio navigation.
• Resolved an issue where agent responses could show duplicate or stacked content in the chat.
• Single questions without follow-up no longer retain context from previous conversations.
• The Slack integration now correctly displays error messages instead of failing silently.
• Canceling an agent response while it's still generating no longer produces error messages.