[Feature]: Support Crof.ai usage

[draxxris]

Before submitting

• I searched existing issues and pull requests for a similar request.

Problem

Requesting support for crof.ai provider. They are per-token billing only, no subscriptions.

Proposed solution

Use the /usage_api/ endpoint and parse the JSON response for key "credits"

Provider

Crof.ai

Platforms

No response

Alternatives or additional context

> curl -H "Authorization: Bearer $CROFAI_API_KEY" https://crof.ai/usage_api/

{
  "credits": 11.19,
  "requests_plan": null,
  "usable_requests": null,
  "usage": {
    "deepseek-v4-flash": {
      "cached_tokens": 10143379,
      "input_tokens": 14240304,
      "output_tokens": 66011,
      "total_tokens": 14306315
    },
    "deepseek-v4-flash-0731": {
      "cached_tokens": 258613946,
      "input_tokens": 337000829,
      "output_tokens": 2921131,
      "total_tokens": 339921960
    },
    "qwen3.5-9b": {
      "cached_tokens": 0,
      "input_tokens": 145096,
      "output_tokens": 1168300,
      "total_tokens": 1313396
    }
  }
}