Add Command Code agent detection and integration

[hubaibmahmood]

Problem

semble install does not detect Command Code (cmd), requiring users to manually configure the MCP server. Command Code fully supports MCP servers via cmd mcp add and stores config in ~/.commandcode/mcp.json under the mcpServers key — the same stdio format used by most other supported agents.

Why semble

Command Code is a terminal-based AI coding agent with a growing user base. Auto-detection would let users run semble install and select Command Code alongside their other agents, consistent with how Claude Code, Codex, Cursor, Gemini CLI, Kiro, OpenCode, GitHub Copilot, VS Code, Windsurf, Zed, Reasonix, and Pi are handled today.

For Command Code specifically, the benefit is significant — it spins up an explore agent that reads the majority of files in a repo for each task, consuming thousands of tokens. Semble's semantic search would let it find relevant code in ~2% of the tokens instead.

Manual setup (current workaround)

Users can currently add semble manually:

cmd mcp add semble --scope user -- uvx --from "semble[mcp]" semble

Or with a direct binary:

cmd mcp add semble --scope user -- /path/to/semble

Proposed solution

Add Command Code as a detected agent in semble install, following the same pattern as existing agents (Claude Code, Cursor, Codex, etc.).

I'm happy to implement this.

[Pringled]

Hi @hubaibmahmood, thanks for creating this issue, would be great if you want to add this to Semble! Here's a good PR for reference: #183, I expect the implementation will be very similar:

• A new file src/semble/agents/commandcode.md(assuming it supports sub-agents)
• A new AgentTarget in src/semble/installer/agents.py

And a small addition to the installation docs in the same style as our other docs.

[hubaibmahmood]

Thanks! I'm working on it now — will open a PR shortly.