FEATURE REQUEST: Interactive “Create Proposal” Dialog on Sponsorships Page

@Saahi30 please assign this to me I want to work on it , I am working on this.
### Is your feature request related to a problem?

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

### Describe the feature you'd like

## 🌟 Feature Description
Add an interactive, multi-step “Create Proposal” popup dialog that appears when users click the **Create Proposal** button on the Sponsorships page.

The dialog should include multiple form sections with modern UI components (sliders, radio groups, checkboxes, selects, and file uploads). It will guide users through the process of crafting a proposal for a sponsorship campaign — all within a single modal, without page navigation.

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## 🔍 Problem Statement
Currently, creators have no integrated way to propose collaborations or sponsorship deals directly on the platform. This feature solves that by enabling an **in-platform proposal workflow**, making the user experience seamless and professional.

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## 🎯 Expected Outcome
- Clicking **Create Proposal** opens a responsive modal dialog.
- Users can navigate through 3 guided steps:
1. **Basic Info** (Brand Name, Campaign Type, Platform)
2. **Campaign Details** (Budget Range, Duration, Deliverables)
3. **Proposal Message** (Personalized pitch, Attachments, Contact Preference)
- Includes progress bar and navigation (`Next`, `Back`, `Submit`).
- On submission, a success message is shown and the form resets.

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## 📷 Screenshots and Design Ideas

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https://github.com/user-attachments/assets/8dc3115f-8f61-4f0f-9477-023b35b42235

## 📋 Additional Context
- File: `src/pages/Brand/CreateProposalDialog.tsx`
- Integrated via `` wrapper around the “Create Proposal” button.
- Fully TypeScript typed with `children: React.ReactNode` props.
- Responsive and accessible (Radix + Tailwind-based).

### Record

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