LineChart data point popup/tooltip is truncated at 320px viewport width

Describe the bug

When a user clicks on a data point in a LineChart at 320px viewport width, a popup/tooltip appears showing the relevant data. However, this popup is being truncated/clipped by the component — the popup content is cut off and not fully visible.

This is a separate issue from #8407 (chart axis truncation at 320px, which has been clarified as acceptable). The popup truncation is a blocker because users cannot read the data values when interacting with the chart on narrow viewports.

Isolated Example

No response

Reproduction steps

1. Render a LineChart with multiple data points
2. Use browser DevTools to set viewport to 320px width
3. Click on any data point in the chart
4. Observe that the popup/tooltip showing the data is truncated/clipped

Expected Behaviour

When a user clicks a data point, the popup must be fully visible and not clipped by the component boundary or viewport edge, even at 320px viewport width.

Screenshots or Videos

UI5 Web Components for React Version

2.26.0

UI5 Web Components Version

2.26.0

Browser

Chrome

Operating System

No response

Additional Context

No response

Relevant log output

Organization

No response

Declaration

• I’m not disclosing any internal or sensitive information.

Start by reproducing the LineChart interaction at a 320px viewport in Chrome, then trace the chart popup or tooltip positioning and clipping behavior. Verify the result by clicking data points near different edges and confirming that the complete data popup remains visible without being cut off.