Context percentage indicator not updated when switching models mid-session

Issue

The context percentage shown in the status line does not recalculate when switching models during a session. It continues to use the original model's context window size.

Steps to reproduce

1. Start a Claude Code session with one model (e.g., Haiku)
2. Switch to a different model mid-conversation (e.g., via model selector)
3. Observe the context percentage indicator—it remains based on the original model's context window

Expected behavior

The context percentage should dynamically update to reflect the current active model's context window size.

Example

• Start session with Haiku (200K context)
• Switch to Opus (200K context)
• Context percentage shows incorrect value based on stale model window

Impact

Misleading context usage information when users switch models.