Add Analytics Dashboard with Performance Tracking and ROI Metrics

### Is your feature request related to a problem?

- [x] Yes, it is related to a problem

### Describe the feature you'd like

Hey team! Hey team!

I've been exploring the platform and noticed that the Analytics page is currently just a placeholder. The homepage advertises "Real-time performance analytics & ROI tracking" as a key feature for brands, but when you navigate to /dashboard/analytics, it only shows the text "Analytics".

I think implementing this feature would be super valuable since analytics is such a critical part of any influencer marketing platform. Both brands and creators need data to make informed decisions.

**What I'm proposing:**

A comprehensive Analytics Dashboard that includes:

**Key Metrics Overview**
- Display cards showing important metrics at a glance:
- - Total views/impressions
- - - Engagement rate (with percentage change indicators)
- - - - ROI calculations
- - - - - Number of active campaigns
- - - - - - Revenue generated
- - - - - - - Audience growth
**Interactive Charts & Visualizations**
- Performance over time (line chart)
- - Campaign comparison view (bar chart)
- - - Engagement breakdown by platform (pie/donut chart showing YouTube, Instagram, TikTok, etc.)
- - - - Audience demographics
**Filters & Controls**
- Date range picker (last 7/30/90 days, or custom range)
- - Filter by specific campaigns or platforms
- - - Export data to CSV for reporting
- - - - Refresh button for updating data
**Why this matters:**

For brands:
- They can track their sponsorship ROI in real-time
- - Make data-driven decisions about which campaigns work best
- - - Compare performance across different creators
For creators:
- Monitor their c

### Record

- [x] I agree to follow this project's Code of Conduct
- [x] I want to work on implementing this feature