Add session usage percentage and weekly limit visualization

[king76]

Hi! Thanks for this great extension.

I would like to suggest adding usage tracking features similar to what's available on the Claude Code web interface at https://claude.ai/settings/usage.

Proposed features: Current session usage display

Show the percentage of the session limit remaining
Display the session duration/time remaining
Weekly limit visualization

Add a graphical representation (similar to the usage chart on claude.ai/settings/usage) showing:

Weekly usage progress
Remaining capacity
Usage history/trend

Rationale:
Having this information directly in VS Code would help users:

Better manage their Claude Code usage throughout the day/week
Avoid hitting limits unexpectedly
Plan their work sessions more effectively

Additional context:
The current Claude Code web interface provides a clear visual dashboard for these metrics, and having similar functionality in the VS Code extension would greatly improve the user experience.

Thanks