Fix blank background when copiloting into an agent from the agent-DM RHP

[MelvinBot]

Explanation of Change

When an owner creates an agent on a wide/split layout, #95631 opens the owner↔agent DM in a dedicated unguarded RHP (AGENT_REPORT) sitting over the guarded Agents settings pane. If the owner then taps Copilot into account from that RHP, the session email flips to the agent, so isAgent becomes true and the guarded AgentsPage central pane returns null — a blank background — until the RHP is closed.

The redirect that should send the guarded pane to Profile lived only inside useFocusEffect, which never fires here because the central pane is mounted but not focused (the RHP holds focus). Closing the RHP finally re-focused the pane and ran the effect, which is why "Profile appears" only after closing the RHP.

This adds a focus-independent useEffect (keyed on the isAgent transition) that runs the same redirect when the guarded pane is mounted-but-unfocused, so the background is corrected immediately instead of rendering blank. The redirect logic is factored into a shared redirectAgentAway callback reused by both useFocusEffect and the new effect; the new effect is skipped while focused since useFocusEffect already covers that case. Because the agent-DM RHP is the topmost modal, the existing dismissModal + deferred-redirect path dismisses it and lands the user on Profile — matching the behavior of the already-guarded copilot path.

Fixed Issues

$ #97843
PROPOSAL:

Tests

1. On a wide/desktop layout, go to Account > Agents and create a new agent.
2. After creation, the owner↔agent DM opens in an RHP over the Agents pane.
3. Open the RHP header (agent name) and tap Copilot into account.
4. Verify the background/central pane is not blank — the app lands on rendered content (Profile / Inbox), never an empty pane.
5. Verify no errors appear in the JS console.

• 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

Verified on the fix branch (web, wide layout). After tapping Copilot into account from the agent-DM RHP, the background is fully rendered — no blank pane. Repeated twice with identical results.

Agents pane with the new agent-DM RHP open (Translator Tess), both agents listed behind

RHP Profile subview showing Copilot into account action, Agents pane visible behind (pre-tap)

Immediately after tapping Copilot into account - Inbox with agent DM fully rendered, no blank background

Agents list showing both agents after copiloting

[MelvinBot]

The two failing checks are review/process gates, not code failures — there's nothing to fix by pushing code.

• checklist (PR Author Checklist) — reports 0 out of 38 items complete. This is the human-only author checklist in the PR description; MelvinBot doesn't fill it out on a person's behalf. mjasikowski needs to complete it.
• Check independent approval (Verify peer review) — the PR currently has REVIEW_REQUIRED with zero reviews. It needs an independent human reviewer to approve.

Every actual code check is green (Bun tests, ESLint, Oxfmt, React Compiler, Storybook, unused styles, knip, all builds, check). The remaining test/typecheck/perf jobs are still pending, not failed.

So no code fix is warranted here — the PR just needs the author checklist completed and an independent review/approval.

[MelvinBot]

Re-checked — nothing has changed since my previous comment. The two remaining failing checks aren't code failures, so there's nothing to push:

• checklist (PR Author Checklist) — 0 of 38 items done; mjasikowski needs to complete the author checklist in the PR body.
• Check independent approval (Verify peer review) — still REVIEW_REQUIRED with zero reviews; needs an independent human reviewer to approve.

All code checks are green (Bun tests, ESLint, Oxfmt, React Compiler, Storybook, typecheck, unused styles, knip, all builds, check). The only other non-green jobs are the perf tests, which are still pending, not failed.