[Bug] Built-in provider StepFun Step Plan (China)「stepfun-step-plan」 has incorrect context parameters for model step-router-v1 #38057

Description

The built-in stepfun-step-plan-cn provider in opencode currently configures step-router-v1 with context parameters that do not match the official Stepfun documentation.

According to Stepfun's official docs, the system automatically routes between deepseek-v4-pro and step-3.7-flash for step-router-v1. Its field constraints are essentially aligned with the underlying DeepSeek engine, so its context specification should match deepseek-v4-pro:
Total context window: 1M tokens
Max output tokens (max_tokens): 384K tokens

However, the current built-in configuration in opencode sets step-router-v1 to 256K / 256K, which causes users cannot fully utilize the model's 1M context window.

Plugins

"cc-safety-net@latest",     "opencode-worktrunk@git+https://github.com/qiyuanhuakai/opencode-worktrunk",     "@cortexkit/opencode-magic-context@latest",     "oh-my-openagent@latest"

OpenCode version

1.18.14

Steps to reproduce

It does not need to be reproduced; this is a built-in setting error.

Screenshot and/or share link

Operating System

Windows 11

Terminal

Windows Terminal