feat: Peak-hour ISP throttling detection and alerts

[ajithakdev]

Summary

Analyze test history to detect if the user's ISP is throttling speeds during peak hours (typically 7 PM – 10 PM) and surface this insight prominently.

Feature

• Analyze stored history (200 entries) for time-of-day patterns
• Detect if speeds consistently drop >40% during evening hours
• Show a "Throttling Detected" badge/alert in the popup
• Include throttling analysis in the PDF health report
• Optional notification: "Your speed drops by 60% most evenings between 8-10 PM"

Why

This is the #1 complaint from ISP customers on Reddit. Having timestamped evidence of throttling is powerful for:

• Calling ISP support with data
• Filing FCC/regulatory complaints
• Deciding whether to switch providers

Implementation

• Add analyzeThrottling() in a new analytics.ts module
• Group history entries by hour-of-day
• Compare peak (7-10 PM) vs off-peak averages
• Surface results in side panel dashboard