v0.90.1

Fixed

• llmdialect/openaichat reads native_finish_reason, the provider's
  own finish reason an aggregator such as OpenRouter passes beside the
  normalized one. A native reason naming the output limit (length,
  max_tokens, max_output_tokens, MAX_TOKENS) is max_tokens
  whatever finish_reason says. OpenRouter reports a response cut at the
  limit inside a tool call's arguments as tool_calls, so the call
  reached the caller as complete with arguments that are not JSON.
• The llmdialect/openaichat stream decoder keeps the IR grammar for
  parallel tool calls whose arguments interleave: a call announced while
  the open call's arguments are not yet one JSON value waits, buffered,
  until they are or the stream ends, and its block then starts with what
  it received. It closed a call's block when the next call began, so
  arguments that arrived after for the earlier call were args deltas for
  a block already stopped, which a consumer that checks the grammar
  refuses. Calls that arrive one after another stream as before.