86919: Message in IOU is not scrolled to when navigating via link, 'submitted' not shown

[abbasifaizan70]

Explanation of Change

This fixes the copied message link for one-transaction expenses. Previously the link pointed at the transaction thread, so opening it hid the parent "Submitted" system message and failed to scroll to the linked message. The copy-link action now uses the displayed (parent expense) report ID; LinkedActionNotFoundGuard also looks up the linked action in the transaction thread so a valid link no longer renders "comment not found"; and usePaginatedReportActions falls back to the newest window instead of an empty list when the linked action belongs to the merged-in thread. Result: the link opens the combined expense view with "Submitted" visible and scrolls to the linked message on first navigation.

Fixed Issues

$ #86919
PROPOSAL: #86919 (comment)

Tests

• Verify that no errors appear in the JS console

Steps:

1. Sign in to ND as User A on the main testing device, and User B on the secondary device
2. As User A, create a workspace, add User B as a member
3. As User B, navigate to the workspace chat
4. Create a manual expense, open the expense details, and click the Submit button
5. Send three messages in the expense details
6. Right-click on the 3rd message - Copy link - send the link in a 1:1 chat with User A
7. As User A, open a 1:1 chat with User B, tap the link from step 6
8. The linked message is scrolled to the message whose link we copied.

Offline tests

Same as tests.

QA Steps

• Verify that no errors appear in the JS console

Same as tests.

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.
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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 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.
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  • 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

Screen.Recording.2026-07-18.at.3.37.35.AM.mov

Android: mWeb Chrome

Screen.Recording.2026-07-18.at.3.42.06.AM.mp4

iOS: Native

Screen.Recording.2026-07-18.at.2.58.01.AM.mov

---

Screen.Recording.2026-07-18.at.2.59.07.AM.mov

iOS: mWeb Safari

Screen.Recording.2026-07-18.at.3.02.19.AM.mov

MacOS: Chrome / Safari

Screen.Recording.2026-07-18.at.2.52.35.AM.mov

[codecov]

Codecov Report

✅ Changes either increased or maintained existing code coverage, great job!

Files with missing lines	Coverage Δ
src/hooks/usePaginatedReportActions.ts	100.00% <100.00%> (+7.31%)	⬆️
src/pages/inbox/LinkedActionNotFoundGuard.tsx	92.64% <100.00%> (+0.84%)	⬆️
...es/inbox/report/ContextMenu/ContextMenuActions.tsx	22.69% <100.00%> (+0.84%)	⬆️
... and 25 files with indirect coverage changes