v1.2.26-open-runtime-fork.1

feat(plugin): forward maxTokens from RuntimeAPI to LLM.stream()

Add optional maxOutputTokens field to LLM.StreamInput and use it as
an override before falling back to ProviderTransform.maxOutputTokens().

The RuntimeAPI's stream() params.maxTokens is now forwarded through
LLM.stream({ maxOutputTokens }), so plugin callers (including the
Dart runtime) can control output token limits per-request.

Previously maxTokens was silently dropped — the Dart side sends
maxTokens for title generation (30), emoji generation (20), and
summaries (maxWords * 2), all of which were ignored, causing
unnecessary token usage and latency.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>