UX Polish: Multiline Chat, Agent Teams, Workspace Rename & More

A quality-of-life update addressing the most-requested user feedback: multiline chat input, agent team grouping, direct agent chat, workspace renaming, improved empty states, better output visibility, and enhanced API key management.

• ›Multiline chat input: use Shift+Enter for new lines, auto-resizing textarea that grows as you type
• ›Agent teams: organize agents into named groups (e.g. CRO, Finance, Content) with visual grouping on the agents page
• ›Click-to-chat: start a conversation with any agent directly from their card on the agents page
• ›Workspace rename: edit workflow names from the workspace dropdown
• ›Improved empty agents page: clearer onboarding with step-by-step guidance and dual CTAs
• ›Better output visibility: widened artifact detection window and fallback messages when tools complete silently
• ›API key management: test keys to verify they work, key age tracking with rotation reminders, and global keys that apply across all workspaces