feat: add API Route as an LLM provider

[DennyHo0917]

Description

Hey 👋

I've added API Route as a new provider option. API Route is an OpenAI-compatible API aggregation platform providing access to Claude 3.7, DeepSeek V3/R1, GPT-4o, Gemini 2.5, Qwen, and more via a single API key with global routing acceleration.

What's in the PR

Following the established pattern for OpenAI-compatible providers (e.g. Tensorix, SiliconFlow, Venice):

• core/llm/llms/ApiRoute.ts — new provider class extending OpenAI with default apiBase: "https://global.api-route.com/v1/"
• core/llm/llms/index.ts — registered in LLMClasses
• core/llm/autodetect.ts — added to templating, image support, and parallel generation
• packages/openai-adapters/ — added to types.ts and index.ts
• gui/src/pages/AddNewModel/configs/providers.ts — added to Add Model UI with AUTODETECT
• gui/public/logos/apiroute.png — provider logo
• docs/customize/model-providers/more/apiroute.mdx & docs/docs.json — documentation guide for Chat, Autocomplete, and Embeddings
• extensions/vscode/config_schema.json — VS Code config schema and descriptions

Usage

{
  "models": [
    {
      "title": "Claude 3.7 Sonnet",
      "provider": "api-route",
      "model": "claude-3-7-sonnet-20250219",
      "apiKey": "YOUR_API_ROUTE_KEY"
    }
  ]
}

Or via YAML:

models:
  - name: Claude 3.7 Sonnet
    provider: api-route
    model: claude-3-7-sonnet-20250219
    apiKey: YOUR_API_ROUTE_KEY
    roles:
      - chat

Users can also pick API Route directly from the "Add Model" GUI with auto-detection.

Checklist

• I've read the contributing guide
• The relevant docs, if any, have been updated or created
• The relevant tests, if any, have been updated or created

Please let me know if any adjustments are needed!

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[DennyHo0917]

I have read the CLA Document and I hereby sign the CLA