Remove /mcp from URLs

Our URLs currently include `⁠/mcp` at the root, for example:

`https://ui.dev-core.mcpd.shoot.canary.k8s-hana.ondemand.com/#/mcp/projects/…`

Because we don't have any other top-level pages, the `⁠/mcp` segment doesn't add value and should be removed.

Could think of redirecting `/mcp` to `/` because of potential existing bookmarks