MAESTRO: docs: Fix and expand group-chat.md documentation accuracy

- Added Beta notice callout (feature shows "Beta" badge in UI)
- Fixed "How It Works" section: added keyboard shortcut (Opt+Cmd+C),
  Quick Actions option, and moderator selection step
- Added Tip callout explaining auto-add participants via @mentions
- Added note about hyphenated names for @mentions with spaces
- Added "Managing Group Chats" section with context menu options
- Added "Input Features" section (read-only, images, prompt composer, etc.)
- Changed inconsistent dashes to em-dashes for consistency

docs/group-chat.md

@@ -4,6 +4,10 @@ description: Coordinate multiple AI agents in a single conversation with a moder
 icon: comments
 ---
 
+<Note>
+  Group Chat is currently in **Beta**. The feature is functional but under active development.
+</Note>
+
 Group Chat lets you coordinate multiple AI agents in a single conversation. A moderator AI orchestrates the discussion, routing questions to the right agents and synthesizing their responses.
 
 ![Group chat](./screenshots/group-chat.png)
@@ -18,12 +22,17 @@ Group Chat lets you coordinate multiple AI agents in a single conversation. A mo
 
 ## How It Works
 
-1. **Create a Group Chat** from the sidebar menu
-2. **Add participants** by @mentioning agent names (e.g., `@Frontend`, `@Backend`)
-3. **Send your question** - the moderator receives it first
-4. **Moderator coordinates** - routes to relevant agents via @mentions
-5. **Agents respond** - each agent works in their own project context
-6. **Moderator synthesizes** - combines responses into a coherent answer
+1. **Create a Group Chat** — Use keyboard shortcut `Opt+Cmd+C` / `Alt+Ctrl+C`, click "+ New Chat" in the Group Chats section of the sidebar, or use Quick Actions (`Cmd+K` / `Ctrl+K`)
+2. **Select a moderator** — Choose which AI agent (Claude Code, OpenCode, or Codex) will coordinate the conversation
+3. **@mention agents** — In your message, @mention any Maestro session (e.g., `@Frontend`, `@Backend`). Agents are automatically added as participants when mentioned.
+4. **Send your question** — The moderator receives it first and decides how to proceed
+5. **Moderator coordinates** — Routes to relevant agents via @mentions, can make multiple rounds
+6. **Agents respond** — Each agent works in their own project context
+7. **Moderator synthesizes** — Combines responses into a coherent answer
+
+<Tip>
+  Agents are automatically added as participants when you or the moderator @mention them. You don't need to pre-configure participants — just @mention any active Maestro session by name.
+</Tip>
 
 ## The Moderator's Role
 
@@ -80,8 +89,29 @@ Remote agents are identified by the **REMOTE** pill in the participant list. Eac
 
 ## Tips for Effective Group Chats
 
-- **Name agents descriptively** - Agent names appear in the chat, so "Frontend-React" is clearer than "Agent1"
-- **Be specific in questions** - The more context you provide, the better the moderator can route
-- **@mention explicitly** - You can direct questions to specific agents: "What does @Backend think?"
-- **Let the moderator work** - It may take multiple rounds for complex questions
-- **Mix local and remote** - Combine agents across machines for maximum coverage
+- **Name agents descriptively** — Agent names appear in the chat, so "Frontend-React" is clearer than "Agent1"
+- **Be specific in questions** — The more context you provide, the better the moderator can route
+- **@mention explicitly** — You can direct questions to specific agents: "What does @Backend think?"
+- **Let the moderator work** — It may take multiple rounds for complex questions
+- **Mix local and remote** — Combine agents across machines for maximum coverage
+- **Hyphenated names for spaces** — If your session name has spaces, use hyphens in @mentions (e.g., `@My-Project` for "My Project")
+
+## Managing Group Chats
+
+Right-click on a group chat in the sidebar to access the context menu:
+
+| Action | Description |
+|--------|-------------|
+| **Edit** | Change the moderator agent or customize its settings (CLI args, path, environment variables) |
+| **Rename** | Change the group chat name |
+| **Delete** | Remove the group chat and its conversation history |
+
+## Input Features
+
+The Group Chat input supports the same features as direct agent conversations:
+
+- **Read-only mode** — Toggle to prevent agents from modifying files (participants receive the mode flag)
+- **Image attachments** — Attach images to include in your message
+- **Prompt Composer** — Open the full prompt composer with `Cmd+Shift+P` / `Ctrl+Shift+P`
+- **Enter/Cmd+Enter toggle** — Switch between send behaviors
+- **Message queuing** — Messages are queued if the moderator or agents are busy