Docs updates for E/A#101048 document blocked export of empty reports

[MelvinBot]

Explanation of Change

Help site follow-up for Expense-Empty report can be downloaded via reconciliation in workspace chat (Expensify/App#101048), which blocked exporting a report that has no expenses from a report's More > Export menu and from the basic CSV / Export current view export on the Reports page. Before that change, exporting an empty report produced an empty file from those entry points; now it shows Download failed with the message You can't export an empty report.

The help site never documented this limitation, so members who hit the modal had nothing to search for. This PR adds one FAQ entry to How to Export Reports explaining why the export is blocked, the exact message shown, how to resolve it, and that a mixed selection of empty and non-empty reports still exports.

What changed

• docs/articles/new-expensify/reports-and-expenses/How-to-Export-Reports.md — new FAQ section Why can't I export a report with no expenses?, plus export empty report and download failed added to keywords so the modal text is searchable.

No change is needed in How to Export Expenses: that article covers selecting expenses on the Expenses page, where the empty-report guard does not apply.

UI labels verified against the live app (web)

Every label used in the new copy was checked in a running NewDot build rather than taken from the source strings: the Spend > Reports navigation, the report header's More button, the Export item, the export template list, and the modal's title (Download failed), body (You can't export an empty report.), and button (Got it).

AI Tests

• Markdown-only change to one existing article; no app code, docs routing, or docs config touched, so no unit tests, lint, or typecheck apply.
• npx cspell could not run in this environment (no network access to install the package). The added copy uses only words already present in the article.
• Verified against docs/HELP_AUTHORING_GUIDELINES.md, docs/HELPSITE_NAMING_CONVENTIONS.md, and docs/TEMPLATE.md: one # title plus # FAQ, ## only, question-word heading, bolded UI labels in exact UI casing, no quotation marks around labels.

Fixed Issues

$
PROPOSAL:

Docs follow-up for #101048 — no separate issue.

Tests

// TODO: The human co-author must fill out the tests you ran before marking this PR as "ready for review"
// Please describe what tests you performed that validates your changed worked.

• Verify that no errors appear in the JS console

Offline tests

QA Steps

// TODO: The human co-author must fill out the QA tests you ran before marking this PR as "ready for review".
// Please describe what QA needs to do to validate your changes and what areas do they need to test for regressions.

• 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

---

@dukenv0307, please review the files changed and confirm they reflect the current behavior. Then post a new comment saying @MelvinBot mark this PR as ready for review.