feat(mcp): add local workspace intelligence v2

[JSONbored]

Parent: #32

Goal

Make local MCP analysis better before a miner opens or updates a PR.

Requirements

• Improve local metadata collection for changed files, validation summaries, branch freshness, pending commits, linked issue refs, test evidence, binary/renamed files, and CI status hints.
• Add better “rerun when” guidance.
• Add optional local scorer diagnostics without uploading source.
• Improve CLI output for analyze-branch, preflight, and agent plan.

Acceptance Criteria

• MCP can separate branch-quality blockers from account/queue blockers.
• Passed validation commands count as test evidence.
• Stale base warnings are clear and actionable.
• Binary/renamed/deleted files are handled safely.
• No source contents are uploaded.

Testing Requirements

This issue must preserve the repo's CI gate:

• npm run test:ci must pass.
• Global coverage must remain at or above 95% for lines, statements, functions, and branches.
• Add or update tests for every new branch, fallback path, sanitizer rule, and regression.
• Add invariant/property-style tests when behavior depends on sorting, gating, public/private boundaries, scoring, queue pressure, or source-upload safety.
• Public GitHub output must be tested against forbidden language: wallet, hotkey, raw trust score, payout, reward estimate, farming, private reviewability, and public score estimate.

Required Test Scenarios

• Renamed files.
• Binary files.
• Deleted files.
• Passed validation command.
• No test file but validation exists.
• Stale base.
• Missing scorer.
• Source-upload guard.