FIX: [UUM-145509] Simulator Plugin disabling input devices always.

[diverges]

Description

Fix an issue where the Simulator Window would disable all input devices while open even though the window was not focused. This caused "Game View" to not properly receive input events.

• Added a UI foldout with helpbox explaining this behavior.
• Used created UIElement to capture the panel InputSystemPlugin connects to.
• Enable/Disable devices based on SimulatorWindow focus state.

Screen.Recording.2026-07-22.094016.mp4

Testing status & QA

Manual Testing.

Added automated tests for:

• ConflictingDevicesAreNotDisabledOnCreate
• ConflictingDeviceAddedWhileSimulatorFocused_IsDisabledThenReenabledOnDestroy
• ConflictingDeviceAddedWhileSimulatorNotFocused_StaysEnabled
• ConflictingDeviceAddedWhileSimulatorNotFocused_StaysEnabled

Overall Product Risks

• Complexity: Low
• Halo Effect: Low, specific to simulator window integration.

Comments to reviewers

Device simulator related fixes.

Checklist

Before review:

• Changelog entry added.
  • Explains the change in Changed, Fixed, Added sections.
  • For API change contains an example snippet and/or migration example.
  • JIRA ticket linked, example (case %%). If it is a private issue, just add the case ID without a link.
  • Jira port for the next release set as "Resolved".
• Tests added/changed, if applicable.
  • Functional tests Area_CanDoX, Area_CanDoX_EvenIfYIsTheCase, Area_WhenIDoX_AndYHappens_ThisIsTheResult.
  • Performance tests.
  • Integration tests.
• Docs for new/changed API's.
  • Xmldoc cross references are set correctly.
  • Added explanation how the API works.
  • Usage code examples added.
  • The manual is updated, if needed.

During merge:

• Commit message for squash-merge is prefixed with one of the list:
  • NEW: ___.
  • FIX: ___.
  • DOCS: ___.
  • CHANGE: ___.
  • RELEASE: 1.1.0-preview.3.

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