Allow configurable usage limit reset times to distribute server load and improve UX

Problem

Currently, all Claude Pro users have their usage limits reset at the same fixed time. This creates several issues:

1. Server Load Spikes: All users globally rush to use the service immediately after reset, creating concentrated load
2. Poor UX for Non-UTC Users: Users in other timezones may hit limits during their prime working hours
3. Predictable Traffic Patterns: Makes capacity planning harder due to artificial usage spikes

## Proposed Solution
Make usage limit reset times configurable with constraints:

### Option 1: User-Configurable Reset Time

• Allow users to set their preferred reset time (e.g., 6 AM in their timezone)
• Limit changes to once per month to prevent abuse
• Default to current behavior for users who don't customize

### Option 2: Automatic Timezone-Based Reset

• Automatically set reset time based on user's detected timezone
• Reset at a consistent local time (e.g., 3 AM local time)

### Option 3: Staggered Reset Windows

• Randomly assign users to different reset times within a window
• Distribute load across several hours instead of one moment

## Benefits

• Reduced Server Load: Spreads usage across 24 hours instead of concentrated spikes
• Better User Experience: Users get fresh limits during their active hours
• Improved System Reliability: More predictable and manageable server capacity
• Global Accessibility: Better experience for users outside UTC timezone

## Implementation Considerations

• Limit reset time changes (e.g., once per month) to prevent gaming
• Maintain current behavior as default for backward compatibility
• Consider impact on billing cycles and usage tracking