fix: home drawer keyboard focus trap [WPB-14804]

[Garzas]

https://wearezeta.atlassian.net/browse/WPB-14804

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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

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What's new in this PR?

Issues

Fixed issues:

• When the home hamburger menu was open, keyboard focus could still move to hidden background content.
• The drawer could not be reliably closed with keyboard navigation.
• Drawer keyboard navigation did not stay inside the drawer items and could expose hidden or stale focused drawer content.
• An empty spacer area inside the drawer could receive focus.

Causes

The home drawer stayed composed while closed and relied mostly on default Compose focus traversal. This allowed hidden drawer content and background screen content to remain reachable depending on focus state.

The drawer item list also had no explicit forward/backward focus loop, and the spacer between top and bottom drawer items could become a focus target.

Solutions

• Added explicit drawer focus handling and focus requesters for first/last drawer items.
• Trapped keyboard focus inside the drawer while it is open.
• Wrapped drawer item traversal so TAB from the last item returns to the first item, and SHIFT+TAB works in reverse.
• Added ESC/Back handling to close the drawer from keyboard navigation.
• Hid background screen semantics and focusability while the drawer is open.
• Disabled drawer item click/focus semantics while the drawer is closed to avoid stale hidden focus.
• Removed the focusable empty drawer spacer.
• Split drawer/scaffold keyboard focus logic out of HomeScreen.kt into HomeScaffold.kt to keep the screen file smaller and easier to review.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 73 lines in your changes missing coverage. Please review.
✅ Project coverage is 49.12%. Comparing base (baa4b99) to head (4dd8f5c).
⚠️ Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
...in/kotlin/com/wire/android/ui/home/HomeScaffold.kt	0.00%	64 Missing ⚠️
...tlin/com/wire/android/ui/home/drawer/HomeDrawer.kt	0.00%	9 Missing ⚠️

❌ Your patch check has failed because the patch coverage (0.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4907      +/-   ##
===========================================
- Coverage    49.28%   49.12%   -0.16%     
===========================================
  Files          648      650       +2     
  Lines        22910    22983      +73     
  Branches      3503     3516      +13     
===========================================
  Hits         11291    11291              
- Misses       10572    10645      +73     
  Partials      1047     1047              

Files with missing lines	Coverage Δ
...tlin/com/wire/android/ui/home/drawer/HomeDrawer.kt	0.00% <0.00%> (ø)
...in/kotlin/com/wire/android/ui/home/HomeScaffold.kt	0.00% <0.00%> (ø)

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[sonarqubecloud]

Quality Gate passed

Issues
2 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