Fixes #4312. Write ViewArrangement tests (#4313)

* Initial plan

* Add comprehensive ViewArrangement unit tests

Co-authored-by: tig <[email protected]>

* Add more comprehensive ViewArrangement tests

Co-authored-by: tig <[email protected]>

* Add view-specific arrangement tests and documentation

Co-authored-by: tig <[email protected]>

* Add MouseGrabHandler tests proving concurrent testing works

Co-authored-by: tig <[email protected]>

* Add proposal for Application.RaiseMouseEvent refactoring

Co-authored-by: tig <[email protected]>

* Add interface design discussion to proposal

Co-authored-by: tig <[email protected]>

* Update proposal with final interface naming: IMouseGrab and IMouse

Co-authored-by: tig <[email protected]>

* Remove refactoring proposal - will be done in separate PR

Co-authored-by: tig <[email protected]>

* Fix build after v2_develop merge - replace Application.MouseGrabHandler with Application.Mouse

Co-authored-by: tig <[email protected]>

* Add 14 more ViewArrangement tests covering flag combinations and edge cases

Co-authored-by: tig <[email protected]>

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Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: Tig <[email protected]>
Co-authored-by: tig <[email protected]>

Author: Copilot