Enrich cross-sector mechanism proof pages

[velvetmonkey]

What changed

• Enriches generated cross-sector pattern summaries with accepted lesson counts and open pressure counts.
• Updates each generated cross-sector pattern page to include:
  • accepted failure chains
  • live bets with review pressure
  • pending review evidence
  • mechanism-specific proof/limits language
• Links the generated proof path to cross-sector mechanisms.
• Adds regression coverage for the new cross-sector summary columns and pattern-page sections.

Why

The current corpus proves individual assumption -> outcome -> lesson chains. This PR makes the next layer visible: repeated mechanisms across sectors, with accepted lessons and live bets under pressure on the same generated pages. That moves the product surface from example tracking toward reusable failure-mechanism discovery.

Verification

• git diff --check passed.
• npm run lint -w @velvetmonkey/flywheel-ideas-core passed.
• npm test -w @velvetmonkey/flywheel-ideas-core -- company-tracker passed: 10 tests.

Risk

Low to moderate. This changes generated Markdown reports only; it does not change SEC ingestion, outcome application, schema, or canonical assumption/outcome semantics. The enrichment intentionally matches accepted lessons/review pressure by theme rather than loose ticker overlap to avoid overstating mechanism evidence.