feat: add highways route convergence analysis

[bntvllnt]

Summary

• add Highways H1 analysis for repeated entry-to-sink routes, bypasses, cowpaths, stable opportunity ids, trace, blast radius, recommendations, and context packs
• expose it through CLI highways, MCP analyze_highways, operation registry parity, hints, docs, llms files, and roadmap
• add chained E2E coverage plus real-codebase verifier coverage for Highways

Validation

• pnpm lint
• pnpm typecheck
• pnpm build
• pnpm test (33 files, 465 tests)
• pnpm verify:cli-real (62 checks, 0 failures)
• git diff --check
• dogfood: affected route dedupe + route shape consistency assertions
• code review artifact: /tmp/code-review-highways-h1.json verdict CLEAN

Notes

• --propose is present for H2 synthesis; H1 always emits agent context packs.
• No stable release in this PR; canary verification follows after merge.