feat: add API Route provider

[DennyHo0917]

Summary

Adds API Route as an OpenAI-compatible multi-model provider.

Provider ID: api-route

API base URL: https://global.api-route.com/v1

Authentication: API_ROUTE_API_KEY

Adds initial catalog entries for:

GPT-5.6 Sol

Claude Sonnet 4.6

Gemini 3.1 Pro

DeepSeek V4 Pro

Grok 4.5

Uses base_model for relayed models and keeps provider definitions override-only.

Sources

Provider documentation: https://www.api-route.com/docs/overview

Pricing and model availability: https://www.api-route.com/pricing

Website: https://www.api-route.com/

Pricing values are in USD per 1M tokens and were checked on 2026-09-18.

Reasoning options follow the underlying lab models and established multi-model relay entries in the models.dev catalog.

[github-actions]

Action items

• [high] [violation] providers/api-route/models/deepseek-v4-pro.toml:3 - Check: Relay reasoning_options must follow the lab + same-surface peer baseline for DeepSeek V4 (not a made-up subset). Why: First-party DeepSeek is toggle + effort high/max; AGENTS.md documents that mapping. This entry uses only ["high", "xhigh"] — no on/off control and xhigh instead of lab max — so callers get the wrong DeepSeek V4 control surface. Action: Align with the lab baseline: toggle + effort ["high", "max"] (with a leading wire-path comment for the toggle), or keep a peer-proven variant only if this host’s docs/API actually expose that exact set.