feat(Layout): add click-to-expand mode for collapsed sidebar

[h2ls]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

When the Layout sidebar is collapsed (IsCollapsed="true"), it automatically expands whenever the mouse hovers over it. In some scenarios this hover-expand behavior is too sensitive — simply moving the mouse across the sidebar area expands it and shifts the layout, which is distracting.

Describe the solution you'd like

Add a new IsExpandOnHover parameter (default true, keeping the current behavior). When set to false:

• Hovering over the collapsed sidebar does not expand it
• Clicking the collapsed sidebar expands it
• Moving the mouse out of the sidebar area collapses it back

<Layout IsCollapsed="true" IsExpandOnHover="false" ...>

Additional context

Implementation ready: the hover-expand rule in Layout.razor.scss is gated behind :not(.is-click-expand), and a click-expand mode toggles an is-expand class via @onclick / @onmouseleave on the sidebar. Unit test IsExpandOnHover_OK added.

[bb-auto]

@h2ls Thank you for contacting us. We will give feedback later.