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>

config.yaml

@@ -0,0 +1,47 @@
+llm:
+  providers:
+    anthropic:
+      model: claude-sonnet-4-5-20250929
+      max_tokens: 8192
+    deepseek:
+      provider: litellm
+      model: deepseek/deepseek-chat-v3.1
+    kimi:
+      provider: litellm
+      model: openrouter/moonshotai/kimi-k2.5
+    minimax:
+      provider: litellm
+      model: minimax/MiniMax-M2.1
+
+channels:
+  cli:
+    enabled: true
+    default_agent: coder
+  discord:
+    enabled: false
+    token_env: DISCORD_BOT_TOKEN
+    default_agent: coder
+    allowed_users: []
+
+tools:
+  workspace: ./data
+  auto_approve:
+    - read_file
+    - list_dir
+    - web_fetch
+    - delegate
+  require_approval:
+    - bash
+    - write_file
+    - edit_file
+
+mcp_servers: {}
+
+agents:
+  coder: agents/coder.md
+  researcher: agents/researcher.md
+  reviewer: agents/reviewer.md
+
+orchestrator:
+  max_concurrent: 5
+  delegation_timeout: 120