v0.2.0

The "trust & distribution" release (SPEC v3.1, Steps 25–31) plus two
multi-agent review hardening passes.

Added

• Eval harness (chief eval): a 200-case golden dataset with strictly
  separated CAPABILITY (improvable, report the number) and REGRESSION evals
  (the demo 24 — 100% forever, CI-gated); bucketed markdown reports by
  route/topic/scene.
• Decision tracing + cost accounting (chief trace <event_id>): per-stage
  latency, tokens in/out/cached, and USD cost on every decision, with
  per-model list prices (DeepSeek cache-hit vs cache-miss modeled explicitly).
  The Tact Report gained a cost dimension: % events reaching the LLM, cache
  hit rate, judgment spend — all windowed to the report period.
• Prompt governance: all prompts are versioned Jinja2 templates
  (judge/templates/v1/); the version is stamped into every judged decision's
  audit record, and chief eval --compare v1 v2 produces an agreement-delta +
  flipped-samples diff. House rule: no prompt change merges without one.
• Graceful degradation: chaos-tested judge failures (malformed JSON,
  timeout, backend down) fall back to rules-only conservative routing — never
  interrupt while blind, never drop — marked degraded=true, auto-recovering,
  and surfaced in chief status.
• chief lite: zero-daemon judgment-only mode (stages 1–3 + routing) for
  one-shot callers and skills.
• Dual skill packaging: Claude Code skill alongside the OpenClaw skill.
• Integration examples (examples/integrations/): a stock-analysis-bot
  feed and a generic webhook template, both runnable offline.
• Quantified README: the first screen leads with numbers regenerated from
  the deterministic demo replay via make readme-metrics, gated by tests.
• Open-source scaffolding: LICENSE (MIT), CONTRIBUTING, CODE_OF_CONDUCT,
  SECURITY, issue/PR templates, examples/, bilingual README, chief --version.

Fixed (highlights from the two review passes)

• Cost accounting: per-model pricing (default gpt-4o-mini configs were billed
  at gpt-4o rates, ~17×); failed retries and mid-retry transport errors are
  billed; a single Decision.cost source of truth.
• Robustness: "usage": null from OpenAI-compatible proxies no longer breaks
  judgments; the Brain's outer judge timeout (150s) now fits HTTPJudge's full
  retry budget; unknown prompt_version fails fast at startup; LLM-echoed
  usage keys are stripped before validation.
• Reserved-namespace hardening: the degradation marker moved to a dedicated
  meta table and externally supplied dunder topics are namespaced at ingest.
• Eval integrity: regression gates before the paid capability run; a broken
  fixture fails loud while a flaky backend degrades a single case instead of
  aborting a paid run; loud warning when "low agreement" is really an outage.