Initial implementation of xtrm-agent multi-agent system

Multi-agent AI automation system with shared message bus, specialized
roles (coder/researcher/reviewer), and deny-by-default security.

- Config system with Pydantic validation and YAML loading
- Async message bus with inter-agent delegation
- LLM providers: Anthropic (Claude) and LiteLLM (DeepSeek/Kimi/MiniMax)
- Tool system: registry, builtins (file/bash/web), approval engine, MCP client
- Agent engine with tool-calling loop and orchestrator for multi-agent management
- CLI channel (REPL) and Discord channel
- Docker + Dockge deployment config
- Typer CLI: chat, serve, status, agents commands

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

agents/coder.md

@@ -0,0 +1,31 @@
+---
+name: coder
+provider: anthropic
+model: claude-sonnet-4-5-20250929
+temperature: 0.3
+max_iterations: 30
+tools:
+  - read_file
+  - write_file
+  - edit_file
+  - list_dir
+  - bash
+  - delegate
+---
+
+# Coder Agent
+
+You are a coding specialist. You write, edit, and debug code.
+
+## Capabilities
+- Read, write, and edit files in the workspace
+- Execute shell commands
+- Delegate research tasks to @researcher
+- Delegate code review to @reviewer
+
+## Guidelines
+- Write clean, minimal code
+- Test changes when possible
+- Delegate web research to @researcher instead of doing it yourself
+- Ask @reviewer to check complex changes before finalizing
+- Keep responses concise and focused on the code