feat: FAQ portal, earnings analytics, sponsor checkout & admin moderation

[AugistineCreates]

This pr closes bakeronchain#144
This pr closes bakeronchain#148
This pr closes bakeronchain#146
This pr closes bakeronchain#147

This PR delivers four frontend features requested across separate issues. Each was committed individually for clean review.

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1�⃣ Advanced FAQ & Help Center Portal (/faq)

• Interactive Accordions — custom-built accessible accordion widgets with smooth chevron-rotate transitions, keyboard navigation, and ARIA attributes.
• Instant Search — client-side keyword filtering that instantly narrows visible FAQ items as the user types.
• Feedback System — thumbs-up/down per answer with visual confirmation.
• Premium Design — glass-morphism cards, gradient accents, dark-mode palette, micro-animations on hover/expand.

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2�⃣ Interactive Earnings & Payout Analytics Charts (Donor page)

• Recharts Integration — area/line charts with gradient fills visualizing earnings over time.
• Time-Interval Selectors — toggle between 7 days, 30 days, and Year-to-Date views.
• Tooltips & Legend — premium hover overlays showing transaction details (volume, gas costs, net royalties).
• Mocked Dataset — realistic sample data for immediate visual demonstration.

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3�⃣ Sponsor a Student Scholarship Checkout (/sponsor/checkout)

• Bulk Address Input — textarea supporting comma/newline/semicolon-delimited addresses + drag-and-drop CSV/TXT file upload.
• Real-Time Stellar Address Validation — checks G-prefix, 56-char length, base32 charset; shows green/red badges with specific error messages.
• Gas Estimation Interface — live cost breakdown: 25 USDC/student license, 0.05 XLM gas buffer/student, USD equivalent, grand total.
• Receipt State — premium invoice panel with mock transaction hash, funded recipients list, copy-to-clipboard, and Stellar explorer link.

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4�⃣ Admin Content Moderation Dashboard (/admin/moderation)

• Moderation Feed — structured table of flagged materials showing title, reporting reason, reporter, and date.
• Action Panel — Approve, Deny, and Suspend buttons wired to POST /api/moderation/:id/:action.
• Auth Gate — redirects unauthenticated users; validates auth token before rendering.
• Consistent Design — glass-card dark-mode UI matching existing admin panel aesthetics.

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Routes Added

Path	Feature
/faq	FAQ & Help Center
/sponsor/checkout	Sponsor a Student Checkout
/admin/moderation	Content Moderation Dashboard

Testing

• Unit tests added for FAQ, Earnings Analytics, and Sponsor Checkout components using Vitest + React Testing Library.
• All components follow existing project patterns (lazy loading, glass-morphism design, Tailwind CSS).