test: cover metro session runtime flows [WPB-25946]

[Garzas]

https://wearezeta.atlassian.net/browse/WPB-25946

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• The PR Title

  • conforms to the style of semantic commits messages¹ supported in Wire's Github Workflow²
  • contains a reference JIRA issue number like SQPIT-764
  • answers the question: If merged, this PR will: ... ³

• The PR Description

  • is free of optional paragraphs and you have filled the relevant parts to the best of your ability

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What's new in this PR?

Adds regression coverage for the Metro session runtime flows that were breaking during the Hilt to Metro migration.

The tests cover:

• login path that reaches the too-many-devices flow,
• cancelling/removing a device from the too-many-devices screen,
• returning from add-account login back to an existing session,
• logout/session transition behavior,
• removed-client event handling when another account is available,
• removed-client event handling when no other account is available.

Why

These scenarios caught the recent runtime regressions around session-scoped Metro graphs, account switching, logout, and client removal. Keeping them covered should make the remaining Metro migration safer and prevent us from reintroducing white screens, stale session graphs, or wrong-account state.

Validation

• Added critical-flow style UI test coverage for the session/account edge cases.
• Branch is stacked on top of fix/metro-session-runtime-stability.

[MohamadJaara]

can you please add it to regression tests please instead of critical flow or sync with @emmaoke-w if it must be in critical?

[pull-request-size]

Ups 🫰🟨

This PR is too big. Please try to break it up into smaller PRs.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 48.93%. Comparing base (363bb88) to head (828633e).
⚠️ Report is 2 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4954      +/-   ##
===========================================
+ Coverage    48.79%   48.93%   +0.14%     
===========================================
  Files          646      646              
  Lines        23159    23168       +9     
  Branches      3545     3552       +7     
===========================================
+ Hits         11300    11337      +37     
+ Misses       10812    10779      -33     
- Partials      1047     1052       +5     

see 1 file with indirect coverage changes

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