Exercise 2: Confirming JavaScript's String Behavior — Possible Solution
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NODE REPL SESSION
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> '水のページ'.length
5
> '水のページ'.slice(0, 3)
'水のペ'

WHAT THIS CONFIRMS
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Per this chapter, JavaScript strings are UTF-16 code unit sequences,
and common kanji characters like 水 fall within the Basic
Multilingual Plane, each represented as exactly one UTF-16 code unit.
.length correctly reports 5 real characters, and .slice(0, 3)
correctly cuts at a real character boundary rather than corrupting a
multi-unit character mid-way through - identical, expected behavior
to the same test already run in the Astro rebuild's own Chapter 7,
since both run on the same Node.js/V8 engine.

WHY THIS WORKS AS AN ANSWER
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It correctly demonstrates real JavaScript string behavior on a
kanji-containing string, confirming this chapter's own claim that
Express inherits the exact same safe string model already relied on
twice before in this series.