Fix sidebar overlapping copyright on tiny screens

[odd-Innocent]

The fixed/sticky sidebar on desktop could overlap with the copyright section (or be inaccessible) on screens with very small height (like mobile devices in landscape mode or resized desktop windows). This fix applies a max-height: calc(100vh - 120px); combined with overflow-y: auto; to .sidebar-inner to allow the sidebar to become scrollable independently if its content is taller than the available viewport.

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PR created automatically by Jules for task 15983649085635106931 started by @odd-Innocent

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