v0.2.1: buggo hunt via MCP

buggo hunt is now available via MCP

buggo hunt shipped as a CLI-only command in 0.2.0 - an agent connected over MCP had no way to invoke it, and buggo init's CLAUDE.md/AGENTS.md instructions never mentioned it. This release closes that gap:

• buggo-mcp now registers a second tool, buggo_hunt, alongside buggo_investigate - takes just { repository }, no bug report needed, shares the same per-session call cap.
• buggo init now writes instructions telling the agent when to reach for buggo_hunt (no known bug yet) vs buggo_investigate (a known bug to localize).

No changes to hunt's ranking logic or CLI behavior - this is purely about making it reachable by agents, not just humans running the CLI.