Add support for the new Structured Output Response Healing plugin

[ejdrien]

The new Structured Output Response Healing (announcement post, docs) is a new plugin that can be enabled per request simply by adding

plugins: [
  { id: "response-healing" },
]

to openrouter provider instance inside generateObject.

This library already supports plugins for previously introduced plugins such as web or file-parser.

This issue asks to add support for this new plugin.

[linear]

from tom.aylott:

just back from company vacation. will get this resolved sooner than later