Add Runner C++ hotkey conflict unit test seed

[crutkas]

Adds the C++ counterpart to #48346: a focused Runner native unit-test seed for core hotkey conflict behavior.

Why this one:

• Runner is core infrastructure rather than another C# module test.
• It adds the missing native C++ test-project path for Runner.
• The seed test is deterministic and covers in-app hotkey conflict detection.
• It keeps the active rollout to two PRs: one C# module-services PR (Add Awake module services unit test seed #48346) and one C++ core/runner PR.

Validation:

• tools\build\build.ps1 -Platform x64 -Configuration Debug -Path src\runner\UnitTests
• vstest.console.exe x64\Debug\tests\Runner\Runner.UnitTests.dll /Tests:HasConflict_TwoModulesSameHotkey_InAppConflict → 1 passed