feat(hermes): consume authoritative local costs

[pitimon]

Summary

• consume explicitly authoritative Hermes per-model costs from local state.db, without any LiteLLM gateway credential, spend-log, database, or network collector
• preserve fail-closed fallback for older schemas, unknown/partial task attribution, and unknown-to-actual transitions
• propagate fixed cost provenance through queue, local API, and dashboard model data; update authoritative privacy/OpenWiki contracts
• add Issue Use gateway spend logs for logical auto-router model pricing #184 OpenSpec proposal and regression coverage for transition, cost-only delta, API, dashboard, and documentation behavior

Verification

• npm run ci:local
• npm --prefix dashboard run typecheck
• npm publish --dry-run for @ipv9/tokentracker-cli@0.39.52 (174 files)

Follow-up

Current Hermes data remains unknown/none; a separate Hermes/gateway change must populate actual_cost_usd with cost_status=actual before live routed traffic can use this path. This PR deliberately does not add any gateway collector or credential.

Closes #184