Memoize script versions per tsc request

Editor assessment

Memoize script versions per tsc request is a precise technical subject: it names the optimization, the cached quantity, and the scope of reuse, which lets a reader grasp the design without the diff. The lsp scope and refactor type fit, and the change is self-contained enough that the absent body is defensible, though the motivating latency pressure is unstated. Hygiene is clean with no footers needed. Publishable with minor flaws. A note on the latency pressure that motivated memoization would be the only addition worth making to this subject.