Add gallery image upload with preview support

[yogesh4216]

Issue: #179

Gallery Photo Upload Support

What’s changed

• Added option to select a single image from gallery
• Shows preview screen before upload
• Reuses existing upload pipeline (no duplicate logic)
• No backend changes
• Camera functionality remains unaffected

Testing

• Tested on Android using Expo Go
• Gallery selection → preview → upload works correctly
• Success confirmation shown after upload

Notes

• No new backend changes
• Follows existing UI and coding patterns

[OpenGitBot]

Hey @yogesh4216

PR Template is not followed. Kindly follow the template & edit it again for consideration as a valid pull request.

Thanks for contributing in OpenCode'25 ✨✨!

Correct Tempelate:
Issue : #<Issue_Number>

[OpenGitBot]

Hey @yogesh4216

Thanks for opening this PR 🚀. Mentor will review your pull request soon and till then, keep contributing and stay calm.

Thanks for contributing in OpenCode'25 ✨✨!

[23abdul23]

@yogesh4216

Bro read the codebase atleast, all the StyleSheet are moved in a seperate folder

`frontend/src/styles/

Move the styling code in there

(you used AI heavily in this 😔)

[yogesh4216]

Thanks for the review 👍
I've moved the CameraScreen styles into "frontend/src/styles/CameraScreen.styles.js" and updated the screen to import them.
Please let me know if anything else needs adjustment.

[23abdul23]

@yogesh4216

Current codebase is in .tsx, but your work is in .js

Convert the code to .tsx and raise a PR Again.