Configurable context window status bar color thresholds per model

Feature Request

Allow users to configure the context window status bar color/gradient thresholds, ideally per model or context window size.

Problem

The status bar color thresholds (yellow/red warnings) are hardcoded and tuned for smaller context windows (~200K). With 1M context window models (e.g., Opus 4.6 with context-1m-2025-08-07), the default thresholds don't provide useful early warnings — by the time the bar turns yellow or red, a significant amount of context has already been consumed.

Desired Behavior

Allow configuration of status bar color thresholds, e.g. in settings.json:

{
  "contextWindowThresholds": {
    "yellow": 0.20,
    "red": 0.30
  }
}

Or ideally, per context window size:

{
  "contextWindowThresholds": {
    "default": { "yellow": 0.60, "red": 0.80 },
    "1000000": { "yellow": 0.20, "red": 0.30 }
  }
}

Why This Matters

• On a 1M context window, 20% usage is already 200K tokens — a substantial amount worth flagging
• Users working with large context models want earlier visual warnings to manage sessions proactively
• The current one-size-fits-all thresholds don't scale across different context window sizes

Environment

• Claude Code CLI
• Model: Opus 4.6 (1M context)
• OS: macOS