Description

Add a configuration option to manually specify the context window size in mycoder.config.js.

Motivation

When using models that are not known by the tool (especially with Ollama where there are many possible models), users need a way to manually specify the context window size so that:

1. Token usage tracking can work correctly
2. Automatic compaction can be triggered when appropriate

Implementation

• Add a contextWindow configuration option to mycoder.config.js
• Update the code to use this configuration when a model's context window is not known
• Update documentation in README.md and packages/docs to explain this feature
• Special focus on Ollama documentation since it supports many different models

Related Issues

• Make model context window optional #362 (Make model context window optional)