🎨 Palette: [UX improvement] Add ARIA labels to primary input fields

[dhaatrik]

💡 What: Added aria-label attributes to the main <input> fields in src/components/Login.tsx (Mobile Number, OTP) and src/components/OrderFuel.tsx (dynamic label for amount/liters).
🎯 Why: These input fields lacked explicit programmatic association with their visible labels or placeholders, which is an accessibility anti-pattern. Adding aria-label improves screen reader compatibility.
📸 Before/After: N/A (Visuals remain the same, changes only impact screen readers).
♿ Accessibility: Improved programmatic association for screen reader users by ensuring the primary interactive input elements have explicit context.

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PR created automatically by Jules for task 1651041371599168824 started by @DhaatuTheGamer

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