[good-first-issue] Fix redundant alt text on GitHub icon in Header

[Metrohan]

What to build / Ne yapılacak

EN: In Header.jsx, the GitHub icon has alt="GitHub" while the adjacent visible text already says "GitHub" — screen readers will announce "GitHub GitHub" for that link. Compare with the coffee-support button right below it, which correctly uses alt="" on its icon since the visible label "Destek Ol" already conveys the meaning. The GitHub icon's alt should be made empty (decorative) for consistency, since the link text already conveys the purpose.

TR: Header.jsx içinde GitHub ikonunun alt="GitHub" değeri var, ama hemen yanındaki görünür metin zaten "GitHub" yazıyor — bu yüzden ekran okuyucular linki "GitHub GitHub" olarak duyuracak. Hemen altındaki kahve/destek butonu ise ikonunda doğru şekilde alt="" kullanıyor çünkü görünür "Destek Ol" etiketi zaten anlamı taşıyor. Tutarlılık için GitHub ikonunun alt değeri boşaltılmalı (dekoratif).

File

frontend/src/components/Header.jsx (around line 75)

Acceptance criteria

• Change alt="GitHub" to alt="" on the GitHub icon <img>, since the adjacent link text already conveys the purpose
• Do a quick audit of other <img> tags in Header.jsx and SupportModal.jsx for the same decorative-vs-meaningful pattern; fix any other clear inconsistencies found and note them in the PR description
• No layout/visual changes
• Verify with a screen reader or axe/Lighthouse that the link is no longer announced redundantly

Blocked by

None — can start immediately.