Fix: use a unique filename for iOS shared images to fix stale receipt preview

[MelvinBot]

Explanation of Change

On iOS, the Share Extension writes every incoming image (screenshots / gallery photos arrive as a UIImage and go through handleImageData) to disk under a constant filename, shared_image.png. Even though setupSharedFolder wipes and rewrites that file on each share, the absolute path — and therefore the file://…/sharedFiles/shared_image.png content URI handed to JS — is byte-for-byte identical every time. The receipt preview binds to that URI, and the image layer (expo-image) keys its cache on the URI, so it keeps serving the first decoded receipt on every subsequent share.

This change gives each shared image a unique filename (shared_image_<UUID>.png) so the resulting content URI differs per share. That single change is the convergence point — the native content, the preview source, and the upload path all derive from this filename — so a distinct URI busts the cache and the newly selected receipt is decoded and shown, with no JS changes. The extension already clears sharedFiles on each run, so unique names never accumulate on disk.

Note for reviewer: Production iOS is the HybridApp, built from the Mobile-Expensify submodule, whose Share Extension has its own handleImageData. This App-repo change covers the standalone iOS build; a paired change to the same function in Mobile-Expensify is needed for the fix to take effect on staging/production. Link that PR via the MOBILE-EXPENSIFY: line below when it's ready.

Fixed Issues

$ #95075
PROPOSAL: #95075 (comment)

Tests

// TODO: The human co-author must fill out the tests performed before marking this PR as "ready for review".

Suggested manual test (iOS Native):

1. Take a screenshot, open the native share sheet, select Expensify, choose a workspace chat, and confirm the preview shows the screenshot you just took. Save it.
2. Take a different screenshot and repeat the share flow.
3. Verify the preview shows the new screenshot, not the previous one.
4. Repeat with several different screenshots and confirm the preview always matches the latest one.

• Verify that no errors appear in the JS console

Offline tests

N/A — native share-file handling; not network dependent.

QA Steps

// TODO: The human co-author must fill out the QA steps before marking this PR as "ready for review".

Same as Tests above.

• Verify that no errors appear in the JS console

PR Author Checklist

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for the expected offline behavior in the Offline steps section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text that was added to the app is grammatically correct in English. It adheres to proper capitalization guidelines (note: only the first word of header/labels should be capitalized), and is either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
• If new assets were added or existing ones were modified, I verified that:
  • The assets are optimized and compressed (for SVG files, run npm run compress-svg)
  • The assets load correctly across all supported platforms.
• If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
• If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
  • I verified that all the inputs inside a form are aligned with each other.
  • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
• I added unit tests for any new feature or bug fix in this PR to help automatically prevent regressions in this user flow.
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

[MelvinBot]

I created this PR from an upstream branch since I don't have push access to your fork.

To take ownership of this branch and be able to push updates, run:

git remote add upstream https://github.com/Expensify/App.git
git fetch upstream claude-shareImageUniqueFilename
git checkout -b claude-shareImageUniqueFilename upstream/claude-shareImageUniqueFilename
git push -u origin claude-shareImageUniqueFilename

Then you can close this PR and open a new one from your fork.

⚠️ Heads up: production iOS is the HybridApp built from the Mobile-Expensify submodule, whose Share Extension has its own handleImageData. This PR fixes the standalone iOS build only — a paired change to the same function in Mobile-Expensify is required for the fix to reach staging/production. Link it via the MOBILE-EXPENSIFY: line in the PR body when ready.

[MelvinBot]

I looked into the failing checks. The only one that's actually failing is PR Author Checklist / checklist — every other check is passing, skipping, or still pending.

That failure isn't a code problem, so there's nothing for me to push. It fails because the author checklist boxes aren't ticked:

You completed 0 out of 38 checklist items with 38 unfinished items
PR Author Checklist is not completely filled out.

How to clear it: the human co-author needs to review and check the boxes in the PR Author Checklist section of the PR description, and fill out the Tests / QA Steps sections (currently marked // TODO). The PR body already notes these are for the human co-author to complete before marking the PR ready for review. Once the checklist is filled out, this check re-runs and passes.

I intentionally didn't modify code here — the checklist is a manual gate, not a bug in the change.