fix(web): keep the final segment of directory paths with a trailing separator - #5460

💭 I'm examining the logic fix in the markdown-links.ts file, specifically the basenameOfPath function, and tracing through an edge case where the path is "/" to verify the fix handles it correctly—though the test seems to reference "/tmp/" instead of the root path. The fix doesn't introduce a regression for the root case since the original code would also produce an empty label. I'm also checking Windows drive roots like "C:" which should return "C:" correctly. Since this is purely a TypeScript logic fix with tests and no UI or CSS changes, it falls outside the scope of the consistency check, so I should report this as all clear. This is a straightforward logic fix with no UI implications, so it's within scope. I'm noting that other files like pierre-icons.ts might have the same issue, but addressing that would be unrelated cleanup outside the current task.