v1.1.48-open-runtime-fork.5

fix(plugin): Add complete model structure to RuntimeAPI fallback

The fallback model was missing required fields like `capabilities`,
`cost`, `limit`, etc. that LLM.stream() expects. This caused errors like
"undefined is not an object (evaluating 'input.model.capabilities.temperature')".

Now creates a complete model object with sensible defaults for all
required fields, enabling RuntimeAPI to work when Provider.getModel()
fails (e.g., for providers not in models.dev like OpenRouter).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>