mohdel v3.0.0

Breaking

• The session control message is { "op": "abort", "callId" }; op: "cancel"
  is no longer recognized.
• An aborted call's done carries warning: 'aborted', was 'cancelled'.
  WARNING_CANCELLED is WARNING_ABORTED.
• The fake adapter's cancel_after mode is abort_after.
• thin-gate: PooledSession::cancel_and_drain is abort_and_drain.
• Rust client: Client::call returns a Call, a Stream of the same events,
  instead of an EventStream.

Fixed

• thin-gate: an abandoned one-shot call no longer costs the pool a session. A
  /v1/embed, /v1/image or /v1/transcription handler dropped mid-exchange
  killed its session with no replacement. The exchange now runs on its own task:
  the session finishes the call and returns to the pool.
• thin-gate: a session acquired while the pool pushed it a new catalog was
  killed with no replacement if the caller left, or the acquire timed out,
  during that write. This hit every route. The refresh now runs on its own task,
  which returns the session to the pool.

Added

• thin-gate: POST /v1/abort with { callId, authId, gate } aborts an
  in-flight /v1/call. The call's stream ends with the session's aborted
  done, with the usage reported before the cut. 202 on delivery, 404 CALL_NOT_FOUND when this gate has no such call in flight, 421 CALL_MISDIRECTED when gate names another gate. handle_abort and
  AbortRequest are exported at the crate root and in the prelude;
  SessionPool::abort(call_id, auth_id) does the same for embedders.
• thin-gate: a /v1/call response from a gate with a session pool carries
  mohdel-gate, a random per-pool token (GATE_HEADER).
• JS client: an abort after the gate has answered posts /v1/abort with the
  call's gate token and keeps reading, so the aborted done carries the partial
  usage, as in-process. It was synthesized with zero usage. An abort before the
  gate answered still drops the request. A refused abort is thrown, and so is
  an abort of a response without mohdel-gate (PROTOCOL_GATE_UNIDENTIFIED).
• Rust client: Call::abort_request() and Client::abort(&AbortRequest).
  coalesce takes any event stream.

Docs

• PROTOCOL.md and GLOSSARY: abort (the caller stops a call on mohdel's
  side; the done's usage is a lower bound) and abandon (the caller drops
  the stream; the done is lost). "Cancel" is reserved for a provider-side
  cancel. §10 documents /v1/abort, the abandon path, and that the wait for an
  aborted done has no limit of its own.
• Lua, Gleam and OCaml clients: closing a stream abandons the call and loses its
  usage; these clients do not send /v1/abort.