feat(dashboard): add Gemini-powered weekly standup generator widget

[Kavurubuvanesh]

Summary

Closes #2579

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Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that changes existing behavior)
• 📝 Documentation update
• ♻️ Refactor / code cleanup (no functional change)
• ⚡ Performance improvement
• 🔒 Security fix
• 🧪 Tests only

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What Changed

Added Gemini-powered weekly standup generator widget.

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How to Test

1. Add your Google Gemini API key to the .env.local file as GEMINI_API_KEY=your_key_here.
2. Start the local development server (e.g., pnpm dev).
3. Navigate to the main dashboard view.
4. Locate the Weekly Standup Generator widget and click Generate Update.
5. Verify the loading state UI triggers correctly, the generated text formats with emojis/line breaks, and the Copy button successfully writes to your clipboard.
6. Optional: Remove the API key from your .env.local temporarily to verify the graceful error-handling state triggers correctly.

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Screenshots / Recordings

Before	After
(No AI widget present on dashboard)

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Accessibility (UI changes only)

• Keyboard navigation works correctly (Button states are tab-focusable)
• Color contrast meets WCAG AA standard (Tailwind blue-600 against dark theme)
• ARIA labels / roles added where needed
• Tested on mobile / responsive layout (Flexbox UI scales cleanly)

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Additional Context

Implemented using the @google/generative-ai SDK and the gemini-1.5-flash model to prioritize generation speed and token efficiency. The Next.js API route is secured with strict prompt constraints to prevent output hallucination, and the client-side component is fully self-contained with independent loading and error states.

[github-actions]

GSSoC Label Checklist 🏷️

@Priyanshu-byte-coder — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus