Implement dynamic font scaling support in `MedicationScreen.tsx`

[success-OG]

Labels: frontend accessibility

Background
src/screens/MedicationScreen.tsx (29 KB) uses fixed font sizes that do not respect the device's accessibility font size setting. Users who rely on large text cannot read medication instructions or dosage information.

What "Done" Looks Like

• Replace all fixed fontSize values with values from the theme that scale with PixelRatio.getFontScale()
• Cap maximum scaling at 1.5× to prevent layout breakage (document this decision)
• Test at system font size settings: Default, Large, Accessibility Extra Large
• Ensure all text remains readable and no layout overflow at maximum supported scale

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Congratulations, @onjehdaniel889-ctrl! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @onjehdaniel889-ctrl: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

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