Redesign widget UI for clearer usage and limit information

[jiahuang97150-create]

What changed

This PR refreshes the widget UI without changing the core usage data flow.

• Reworked the detailed and compact layouts to improve information hierarchy.
• Reorganized the 5-hour and weekly limit cards, remaining/used values, and reset details.
• Clarified the account and limit summary treatment.
• Improved Token Activity presentation, date-axis labels, progress rendering, typography, spacing, and dark visual styling.
• Improved taskbar label content and hover behavior while preserving existing display modes.
• Added bundled font assets for consistent CJK and numeric rendering.
• Added and updated tests for the new presentation and formatting behavior.

Why

The previous UI stacked related information vertically and made the main usage state harder to scan. This version surfaces the two primary limits first and groups supporting information into clearer sections.

Validation

• dotnet restore .\CodexUsageWidget.slnx
• dotnet test .\CodexUsageWidget.slnx -c Release
• Result: 193 tests passed.
• Fresh local visual smoke renders were checked for the baseline and ui-redesign views.

Screenshots

The following screenshots were uploaded from the latest UI pass:

Screenshot 1

Screenshot 2

Screenshot 3

Screenshot 4

Core usage acquisition and limit calculation logic are unchanged.

[ognjeeen]

Hey @jiahuang97150-create, thank you for wanting to contribute to Codex Usage Widget! Right now I'm quite satisfied with how the widget looks and I don't plan on changing it, but I will be adding a few additional themes soon, so you can check those out when they're ready.

I'll be closing this PR for now, but thank you so much again for taking the time and wanting to contribute to the project. 🙏