roadmap(pillar 5): MCP miner intelligence deepening

[JSONbored]

Parent roadmap: #525

Goal

Deepen the miner-facing MCP surface with deterministic, metadata-only tools that give contributors gittensor-native judgment their AI harness can't compute — before and during a contribution — to reduce wasted work and raise PR quality. All tools reuse the existing signal engine, take no source upload, and make no GitHub writes.

Surface note: the miner MCP spans two layers — tool logic + registration in src/mcp/server.ts (the Worker /mcp gateway, 29 tools today) and exposure in the published package packages/gittensory-mcp/bin/gittensory-mcp.js. New tools touch both, plus any new underlying logic in src/.

Children

• feat(mcp): gittensory_check_before_start (pre-start duplicate/solvability check) #545 — gittensory_check_before_start (pre-start duplicate/solvability)
• feat(mcp): gittensory_validate_linked_issue #546 — gittensory_validate_linked_issue
• feat(mcp): gittensory_explain_score_breakdown #547 — gittensory_explain_score_breakdown
• feat(mcp): gittensory_remediation_plan #548 — gittensory_remediation_plan
• feat(mcp): gittensory_lint_pr_text (commit/PR-body rubric linter) #549 — gittensory_lint_pr_text
• chore(mcp): add outputSchema to tools that lack it #550 — add outputSchema to tools lacking it

Done when

• A miner can check for duplicate/unsolvable work before writing code, validate the linked-issue multiplier, understand their score, get an ordered fix-it plan, and lint PR text against the gittensor rubric.

Cross-cutting acceptance criteria

Inherits the wave criteria (#525): npm run test:ci, 97%+ coverage, no source upload, public/private output boundary, advisory-only.