feat: add Olympus metrics spine

[AIEngineerX]

Summary

• add aggregate-first Metrics Spine v1 to Olympus overview/tuning payloads
• render Metrics Spine in Diagnostics without creating a usage-ledger clone
• aggregate Hermes profile state/skill usage with cost-confidence and privacy safeguards
• ignore generated outputs artifacts for OSS hygiene

Verification

• npm run verify
• npm run test:visual
• npm run test:security
• npm run test:performance
• npm run test:compat
• npm run test:desktop
• OLYMPUS_SMOKE_URL=http://127.0.0.1:9124/olympus npm run test:live
• npm audit --audit-level=moderate