Feature Request: Support LC_TIME locale for /usage command time formatting

Description

The /usage command currently displays times in 12-hour format (e.g., "5am", "6pm") regardless of the system's LC_TIME locale setting.

Current Behavior

Current session
██████████████████████████████████▌   69% used
Resets 5am (Europe/Saratov)

Current week (all models)
███████████████████████████████████████████▌   87% used
Resets 6pm (Europe/Saratov)

Expected Behavior

When LC_TIME=en_GB.UTF-8 (or other locales that use 24-hour format) is set, the times should be displayed in 24-hour format:

Current session
██████████████████████████████████▌   69% used
Resets 05:00 (Europe/Saratov)

Current week (all models)
███████████████████████████████████████████▌   87% used
Resets 18:00 (Europe/Saratov)

Environment

• OS: Linux (WSL2)
• Claude CLI version: 2.1.2
• LC_TIME is properly set in environment: LC_TIME=en_GB.UTF-8
• System locale is configured and generated: locale-gen en_GB.UTF-8

Steps to Reproduce

1. Set export LC_TIME=en_GB.UTF-8 in .bashrc
2. Generate locale: sudo locale-gen en_GB.UTF-8
3. Verify locale is active: locale | grep LC_TIME shows LC_TIME=en_GB.UTF-8
4. Launch Claude CLI
5. Run /usage command
6. Observe that time is still shown in 12-hour format (5am, 6pm) instead of 24-hour format (05:00, 18:00)

Proposed Solution

Respect the system's LC_TIME locale setting when formatting timestamps in the /usage command output. This would make Claude CLI more internationally friendly and consistent with user expectations based on their locale settings.

Additional Context

Many international users prefer 24-hour time format, which is the standard in most countries outside the US. Respecting the LC_TIME locale would make the CLI experience more localized and user-friendly.