feat: Add Pollution Prediction page (prediction.html)

[Riya-Kharade]

📌 Description

This PR introduces a new Pollution Prediction page to EcoPulse.

The page simulates AI-based forecasting by predicting next year's pollution
levels using mock historical trend data.

closed #287

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✨ Changes Made

• Created new file: prediction.html
• Added city selection dropdown
• Added pollution type filter
• Implemented mock prediction logic
• Integrated Chart.js line chart visualization
• Added confidence level indicator
• Applied responsive eco-themed design
• Added navigation back to homepage

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🎯 Purpose

This feature:

• Adds futuristic AI-style forecasting capability
• Enhances analytical depth
• Improves user engagement
• Strengthens hackathon and portfolio presentation
• Makes EcoPulse look research-oriented and data-driven

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🧪 Testing

• Verified prediction generation logic
• Tested chart updates dynamically
• Checked confidence level display
• Ensured responsive layout

Screenshot

No backend changes were introduced.