Add user-configurable context window size override for non-Claude models #345

Problem

When using non-Claude models (e.g., custom API proxies or third-party models) with Claude Code, the context_window_size passed to ccstatusline via the JSON pipe defaults to 200,000 tokens. This is hardcoded in Claude Code's internal model database and cannot be overridden without also disabling the /compact command (via DISABLE_COMPACT + CLAUDE_CODE_MAX_CONTEXT_TOKENS environment variables).

ccstatusline's getContextConfig() function (in src/utils/model-context.ts) trusts the context_window_size value from Claude Code when it's a valid positive number, and never falls back to parseContextWindowSize() model name parsing. This means even if the user appends a context hint like (1m) to the model identifier, it has no effect.

Example

Using a model like mimo-v2.5-pro with a 1M context window via a third-party API proxy shows 200k in the status line instead of 1M.

Proposed Solutions (any one would work)

1. Add a contextWindowOverride setting in ~/.config/ccstatusline/settings.json that takes precedence over the value from Claude Code:

   {
     "contextWindowOverride": 1000000
   }

2. Support an environment variable like CCSTATUSLINE_CONTEXT_WINDOW_SIZE that overrides the JSON value.

3. Fall back to model name parsing even when context_window_size is provided — use parseContextWindowSize() as a secondary check on the model identifier, preferring its result if the Claude Code value looks like a default (e.g., exactly 200000).

Option 1 or 2 would be the most straightforward and non-breaking. Option 3 could cause regressions for Claude model users.

Context

• ccstatusline version: 2.2.10
• Claude Code version: 2.1.119
• The parseContextWindowSize() regex already handles patterns like (1m), [1m], 1M context — it just never gets called when Claude Code sends a valid number.