feat: Campaign share toolkit with OG images, QR codes, and share links

[dotunv]

Overview

Add a per-campaign share toolkit: unique shareable links, QR codes, social-card (OG image) generation, and a shareable pre-filled contribution intent.

Motivation

Viral growth depends on easy sharing. Many existing tools support sharing via platform links, but the campaign pages lack share-optimized images (OG tags/thumbnails) that render correctly when pasted into X, WhatsApp, or other apps, hurting click-through rates.

Proposed Design

1. Auto-generate an Open Graph image per campaign: title, creator, progress bar, "Get funded" CTA, rendered to a PNG served at a deterministic URL
2. Ensure campaign page already includes OG meta tags referencing that image (title, description, image, url)
3. Add a Share modal with: copy link, social buttons (X, LinkedIn, WhatsApp, Telegram), and a QR code of the campaign URL
4. Support a share-to-contribute deep link that pre-selects an amount (?amount=50)
5. Track share clicks to attribute subsequent contributions to a share source when possible

Acceptance Criteria

• Each campaign has a generated OG image served at a stable URL
• Campaign page includes correct OG title, description, image, and url meta tags
• Share modal offers copy-link and social share buttons
• QR code renders the campaign URL and is scannable
• Deep link with amount preselects that contribution amount
• Share modal is accessible from both creator dashboard and public campaign page
• OG image generation works for campaigns without custom images (falls back to defaults)
• Tests cover: OG meta tags, deep-link amount parsing, share URL generation

[Teejay2696]

@Teejay2696 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I'm available to take up this issue immediately

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[Danielkallala]

@Danielkallala has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello,
Thank you for the opportunity to review this issue . After carefully going through the requirements, I am confident that this task is an excellent match for my expertise and experience. I have successfully completed similar projects in the past and am fully prepared to deliver high-quality results that meet your expectations.

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