v0.4.0

Added

• Reserve-mode model and tool gates now use the Python SDK's managed
  reservation lifecycle: server-authoritative heartbeats, a pending-commit
  journal written before the first settlement request, restart replay, and
  /v1/events recovery after reservation expiry.
• openai_cost accepts cached_prompt_per_million_usd;
  anthropic_cost accepts cache-read, generic cache-creation, and distinct
  5-minute/1-hour cache-creation rates. All rates are validated and cache
  counts are read from normalized
  AIMessage.usage_metadata.input_token_details.

Changed

• Raised the runcycles floor to >=0.5.3 and the package version to 0.4.0.
• settlement_error_policy now controls surfacing only. Both policies retain
  known spend for durable recovery; "raise" surfaces CyclesProtocolError
  after recovery is queued, while "log" returns the handler result.
• Caller-derived tool reservation keys continue to flow through the managed
  lifecycle, including deterministic commit and release key derivation.
• Removed the stale unpublished docs/runcycles.mdx mirror. The README and
  the Cycles website are the maintained package documentation.

Fixed

• Long-running handlers no longer outlive an unextended 60-second reservation.
• A transient commit failure can no longer disappear when the process exits,
  and a commit rejection after known spend no longer triggers a release.
• Oversized namespace/tool-call key combinations now use a bounded,
  deterministic SHA-256 form instead of violating the protocol key limit.
• Documentation now distinguishes completed-stream guarantees from interrupted
  streams, which may require provider-billing reconciliation because LangChain
  has not produced finalized normalized usage.