Fall back to live Onyx personal details for the payer in flat Search transaction rows

[MelvinBot]

Explanation of Change

In the Spend list (and any flat Search transaction view), the payer (from) was resolved only from the Search snapshot's personalDetailsList. When an expense is moved to the self-DM (Report and remove from report) while offline, the actor isn't yet in that snapshot, so from fell back to emptyPersonalDetails and the username/avatar rendered blank until the app reconnected and the server snapshot arrived.

This gives the flat transaction path (getTransactionsSections) the same live-Onyx fallback the grouped/expense-report path (getReportSections) already uses: it merges live Onyx personal details into the snapshot map (snapshot still wins where present, live only fills the gaps) and resolves from/to from that merged map. Because from is the object handed to UserInfoCell, this fixes both the missing name and the missing avatar. On reconnect the server snapshot continues to take precedence, so nothing else changes.

getSections already receives onyxPersonalDetailsList; it just wasn't forwarded to getTransactionsSections. The shared mergePersonalDetailsLists helper was moved above getTransactionsSections so it can be referenced there.

Fixed Issues

$ #97481
PROPOSAL: #97481 (comment)

Tests

• Verify that no errors appear in the JS console

Offline tests

QA Steps

// TODO: These must be filled out, or the issue title must include "[No QA]."

• 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]

The only two failing checks here aren't code failures — they're process checks that need a human, so there's nothing for me to push a fix for:

• PR Author Checklist / checklist — failing because the checklist boxes in the PR description are still unchecked ("PR Author Checklist is not completely filled out. Please check every box"). This has to be filled out by a person; I can't tick those boxes for you. (It also flags that MelvinBot isn't verified as an engineering member, so the author-authorization path can't auto-pass it.)
• Check independent approval — waiting on an independent reviewer approval, not a code change.

Every actual CI check is green: Bun tests, all test (job 1–8), typecheck, ESLint, Oxfmt, Storybook tests, React Compiler Compliance, builds, and codecov. The baseline-perf-tests / branch-perf-tests are still pending, which is normal.

So no code fix is needed — please fill out the PR Author Checklist and get a reviewer to approve, and the remaining checks will clear.

[MelvinBot]

Nothing has changed since my previous analysis — the same two checks are the only ones failing, and neither is fixable by pushing code:

• PR Author Checklist / checklist — the checklist boxes in the PR description need to be ticked by a person.
• Check independent approval — needs an independent reviewer to approve.

All actual CI (tests, typecheck, ESLint, builds, codecov) is green; baseline-perf-tests is still pending, which is normal. There's no code fix to push here — please complete the PR Author Checklist and get a reviewer approval to clear these.