feat(mcp): ship native resources prompts and output schemas

[JSONbored]

Parent roadmap: #127
Parent phase: #269

Goal

Make the MCP package feel native to modern MCP clients by exposing resources, prompts, and structured tool output instead of only command-like tools.

This issue is now a mini-epic. Do not implement resources, prompts, and schemas in one PR; use the focused child issues below.

Child issues

• feat(mcp): add structured output schemas for existing tools #291 add structured output schemas for existing tools
• feat(mcp): expose decision-pack and doctor resources #292 expose decision-pack and doctor resources
• feat(mcp): add miner planning prompts #293 add miner planning prompts
• feat(mcp): add maintainer and repo-owner workflow prompts #294 add maintainer and repo-owner workflow prompts
• test(mcp): add resource and prompt discovery fixtures #295 add resource and prompt discovery fixtures

Done when

• Existing tools have structured output schemas.
• Decision-pack and doctor/status state are exposed as resources where appropriate.
• Miner, maintainer, and repo-owner prompts are discoverable and public-safe.
• MCP discovery fixtures cover resources and prompts.

Non-goals

• No raw source upload.
• No autonomous issue filing, PR creation, comments, labels, closure, or merge behavior.
• No public reward prediction, public scoring, wallet, hotkey, raw trust, private scoreability, or private reviewability output.

Validation expected

• Child PRs should include MCP discovery/schema tests, npm run build:mcp, npm run test:mcp-pack, and npm run test:ci.