feat: Multi-language campaign content with auto-translation

[dotunv]

Overview

Allow campaign creators to provide translated versions of their campaign content, and let contributors view campaigns in their preferred language using the existing i18n infrastructure.

Motivation

CrowdPay already supports en/fr UI translations, but campaign content (title, description, milestones) is always in the creator's language. This limits reach in multilingual regions where contributors might skip campaigns they cannot read.

Proposed Design

1. Add a campaign_translations table: campaign_id, locale, title, description, milestone_titles
2. Campaign creation/edit form gets a "Add Translation" button per supported locale
3. Creators can optionally add translations; if none exist, original content is shown
4. Contributor UI respects their locale setting and shows translated content when available
5. Falls back to original language if translation is missing for the contributor's locale
6. API: GET /api/campaigns/:id?locale=fr returns translated fields when available

Acceptance Criteria

• Campaign edit form supports adding translations for each supported locale
• Translations are stored in a separate table (not modifying original content)
• API returns translated fields when locale query param matches an available translation
• API falls back to original language when translation is unavailable
• Campaign page renders in contributor's preferred language
• Missing translations do not break the campaign page
• Translations can be added after campaign launch
• Unit tests cover translation retrieval, fallback, and locale matching

[Peolite1]

@Peolite1 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I would love to work on this issue

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[DTech-Wiz1]

@DTech-Wiz1 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Please let me fix this for you ASAP.

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[okaforwisdom664-lgtm]

@okaforwisdom664-lgtm has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Please assign me to this case

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[Peaostrel]

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

i can handle this quickly

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[GazzyLee]

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

hello, I’d like to take this on. I’ll add the campaign translation model and CRUD flow, wire locale-aware API responses with a fallback to the original content, and update the contributor UI to use their preferred language. I’ll also cover retrieval, locale matching, fallback behavior, and post-launch translations with tests.
ETA is in4 hours tops, please assign

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[veloura-dev]

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

pls maintainer ...I understand what's being asked here and I'm confident I can implement an accurate fix correctly and efficiently. pls assign

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