Fix: close expense creation RHP when clicking outside the open recipient list

[MelvinBot]

Explanation of Change

In the new manual expense flow (gated behind the NEW_MANUAL_EXPENSE_FLOW beta), the recipient list ("To" field) is rendered as a separate RIGHT_DOCKED Modal (ParticipantPicker) stacked on top of the expense-creation RHP. Clicking outside the panel only fired the picker's onClose, which just flips the picker's local visibility state — it never dismissed the underlying expense-creation RHP. So an outside click closed only the recipient list and left the expense RHP open, contradicting standard RHP behavior (clicking outside an RHP closes it).

This was the root cause of the deploy blocker originally surfaced when the beta was removed in #94134 (since reverted by #94312). The flow still has the bug behind the beta, so this PR fixes it directly.

Fix: The Modal component already exposes a backdrop handler (onBackdropPress) that is distinct from the back button. This PR:

• Adds an optional onBackdropPress prop to ParticipantPicker and forwards it to its Modal. When omitted, the Modal falls back to onClose, so existing behavior is unchanged for any other usage.
• In IOURequestStepConfirmation, wires onBackdropPress to Navigation.dismissModal() so an outside/backdrop click dismisses the entire expense-creation RHP.

The header back button (onBackButtonPress → onClose) is intentionally left untouched, so pressing the back arrow still returns to the confirmation form, while clicking outside now closes the whole flow as expected.

Fixed Issues

$ #94246
PROPOSAL: #94246 (comment)

Tests

1. Enable the NEW_MANUAL_EXPENSE_FLOW beta.
2. Go to FAB > Create expense > Manual.
3. Open the confirmation page and click the To field to open the recipient list.
4. Click outside the panel (on the dimmed backdrop area).
5. Verify the entire expense-creation RHP closes (not just the recipient list).
6. Re-open the recipient list and instead press the back arrow in the header — verify it returns to the confirmation form (does not close the whole RHP).
7. Verify that no errors appear in the JS console.

Offline tests

Same as tests (this is a navigation/UI-only change with no network dependency).

QA Steps

1. Enable the NEW_MANUAL_EXPENSE_FLOW beta.
2. Go to FAB > Create expense > Manual.
3. Open the confirmation page and click the To field to open the recipient list.
4. Click outside the panel.
5. Verify the entire expense-creation RHP closes.
6. Re-open the recipient list, press the header back arrow, and verify it returns to the confirmation form.
7. Verify that no errors appear in the JS console.

• 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)
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• 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 any new file was added I verified that:
  • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
• If a new CSS style is added I verified that:
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• 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

MacOS: Desktop

[codecov]

Codecov Report

❌ Looks like you've decreased code coverage for some files. Please write tests to increase, or at least maintain, the existing level of code coverage. See our documentation here for how to interpret this table.

Files with missing lines	Coverage Δ
src/components/ParticipantPicker.tsx	95.00% <ø> (ø)
...es/iou/request/step/IOURequestStepConfirmation.tsx	64.96% <0.00%> (-0.21%)	⬇️
... and 13 files with indirect coverage changes

[MelvinBot]

🤖 Fixed the failing PR Author Checklist / checklist check.

It wasn't failing on unchecked boxes — it was crashing with TypeError: Cannot read properties of undefined (reading 'split'). The authorChecklist action splits the PR body on ### PR Author Checklist … ### Screenshots/Videos, but the generated PR description was missing both sections, so the parser threw before it could evaluate anything (authorChecklist.ts:49-50).

Fix: Restored the standard ### PR Author Checklist and ### Screenshots/Videos sections in the PR description (boxes left unchecked).

The check now runs correctly and reports the normal "PR Author Checklist is not completely filled out" state — thelullabyy, please tick the checklist boxes and add the platform screenshots/videos before marking this ready for review.

All other checks (tests, typecheck, ESLint, Prettier, build, etc.) are passing; the *-perf-tests jobs are non-blocking.

[thelullabyy]

@MelvinBot Please merge main. After that replace all [ ] characters in PR description by [x]. Finally, open this PR for review

[melvin-bot]

@thelullabyy Please copy/paste the Reviewer Checklist from here into a new comment on this PR and complete it. If you have the K2 extension, you can simply click: [this button]

[MelvinBot]

🤖 Done, @thelullabyy:

1. Merged main into claude-fixParticipantPickerBackdropClose (merge commit c5d9ab0, no conflicts) and pushed.
2. Replaced all [ ] with [x] in the PR description — 42 checkboxes updated, 0 unchecked remaining.
3. Marked the PR ready for review (no longer a draft).

[trjExpensify]

Keep 'em coming! 👍