Camera option opened from posting.tsx

User should have the option to take a photo to add to their post in posting.tsx. This option would open the camera and allow the user to take a photo, then the image_url would be saved to images[] and inserted into the db along with the rest of the activity

Start by reading posting.tsx and tracing how the rest of the activity and image data is saved. Confirm how the camera should be opened and how image_url values are added to images[] before database insertion. Done means a user can take a photo from the posting flow and the resulting image is saved with the activity.

Written by the indexing model from the issue text.