[Bug] Context usage indicator shows 0% while /context command shows actual usage

Bug Description
Title: Context usage indicator shows 0% while /context command shows actual usage (33%)

Description:
The context usage indicator in the main interface shows 0% at the start of a session, while the /context command correctly displays the
actual usage.

Steps to reproduce:

1. Start a new Claude Code session with a project containing CLAUDE.md
2. Observe the context indicator in the UI (shows 0% or very low)
3. Run /context command
4. See actual usage: 33% (66k/200k tokens)

Expected behavior:
Context indicator should reflect actual token usage including system prompt, tools, and memory files.

Environment:

• Platform: Windows
• Claude Code model: claude-opus-4-5-20251101
• Terminal: VS Community PowerShell

Environment Info

• Platform: win32
• Terminal: visualstudio
• Version: 2.0.60
• Feedback ID: 9e11361b-9d3f-4d7d-b6cc-80ce7fea018a

Errors

[{"error":"AbortError: The operation was aborted.\n    at unknown\n    at abortChildProcess (node:child_process:947:42)\n    at onAbortListener2 (node:child_process:35:24)\n    at abort (unknown)\n    at <anonymous> (B:/~BUN/root/claude.exe:4777:18007)","timestamp":"2025-12-08T14:55:57.233Z"}]