Summary

When a TestCaseElement is rendered together with its only TestMessageElement child (the result tree compresses single-message test rows), the inline action bar in TestRunElementRenderer.renderCompressedElements is built for the parent element. The right-click handler in OutputPeekTree.onContextMenu, however, was operating on the compressed-in TestMessageElement returned by the tree. This left the right-click menu missing useful actions like Run Test and Debug Test even though those very same icons were visible in the inline action bar on the same row.

This change introduces a small getRenderedElement helper that mirrors the renderer's compression logic and uses the resulting element when computing actions and the action context for the right-click menu, so the menu now matches the inline action bar shown on the visible row.

Fixes #296078

Test plan

• Run a project with failing tests (e.g. C# Dev Kit / pytest with one error message per test).
• In the Test Results view, hover a failed test row whose error message is compressed into the same row and confirm the inline action bar shows Run Test / Debug Test icons.
• Right-click the same row and verify the context menu now includes the same Run Test / Debug Test entries (in addition to Go to Error / Reveal in Test Explorer / etc).
• Right-click an expanded standalone TestMessageElement and confirm it still shows message-specific actions.
• Right-click a TestCaseElement (not compressed) and confirm behavior is unchanged.