Fix random clipping of session contents

[IgorWarzocha]

Problem

Session contents are being clipped unexpectedly in the runtime/session view. In the attached screenshot, message text and lower session output are cut off on the right side while the floating action buttons remain visible, which makes the transcript hard to read and suggests the content container or scroll area is constrained incorrectly.

Scope

• Investigate the session transcript/content layout for unexpected clipping or overflow constraints.
• Fix the container sizing/overflow behavior so messages and runtime output use the available width correctly.
• Check the interaction with floating session controls so they do not mask, squeeze, or force clipping of transcript content.
• Preserve normal scrolling behavior and existing session controls.

Acceptance criteria

• Session message text is not randomly clipped horizontally in the main session view.
• Runtime output and exit/status text remain readable across typical window sizes.
• Floating action buttons do not overlap or constrain the readable transcript area in a way that hides content.
• The fix is validated at a narrow window size similar to the screenshot and at a normal desktop width.

Evidence

Screenshot from the reported state shows content clipped on the right edge while the floating controls are still visible.