Define the time horizon for Borrow

Why is this change being made?

In the Product Bi-weekly, @clefelhocz1 presented the recent changes to global prioritization in !91724 (merged). Upon explanation, it became clear that Borrows still have a time horizon, which is less than 6 months and the primary purpose is to align management structures. This MR clarifies both of those elements for Borrows.

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