[Compiler Bug]: Incorrect closure hoisting causes runtime error

### What kind of issue is this? - [x] React Compiler core (the JS output is incorrect, or your app works incorrectly after optimization) - [ ] babel-plugin-react-compiler (build issue installing or using the Babel plugin) - [ ] eslint-plugin-react-compiler (build issue installing or using the eslint plugin) - [ ] react-compiler-healthcheck (build issue installing or using the healthcheck script) ### Link to repro https://playground.react.dev/#N4Igzg9grgTgxgUxALhAgHgBwjALgAgDMoA7OXASwhPzhgQENcEBlCAWwVwAsKSBzABQAdEgEp8wUflrUwBeTgT4AvPhIIA7vjacWuJYLEBuafjNw5BAMLtMq-EdUA+SWZmWS8-BABGYBBgANwQAE30lBygAgBkIOAYAGwB5f0Cghl9EhEEnFVdFehNRd3x6XFgaERoZWoAeUIog52A-AOCwiPoAOmZ5AF86gHpG5tLimv7TEjNyyvxbTFF+0RAAGhBPQgp+FBAKOxwCXABPTGVgfAAFRKh+PmTMSjl8fqIYDnwAcl9MhESALSYW73EgA+gMcgAyx2CjZGAjCjyL7TUSCKQ1IZDGGYOFMKgkACyEFCCGQ5hASUSwhAy3wYHxYG2CDA1xBDyeBLAJnW4G4EE0AEkSMwYCQkmAUIQJQh+kA ### Repro steps The React Compiler incorrectly hoists closure-scoped variables to the top level when it detects they’re only used inside a closure. This optimization breaks lexical scoping and leads to runtime errors because the moved variable is no longer properly bound. Original Code ``` export function createSomething() { const store = new SomeStore(); const Cmp = () => { const observedStore = useLocalObservable(() => store); return <div>{observedStore.test}</div>; }; return Cmp; } ``` Compiler Output ``` import { c as _c } from "react/compiler-runtime"; export function createSomething() { const store = new SomeStore(); const Cmp = () => { const $ = _c(2); const observedStore = useLocalObservable(_temp); let t0; if ($[0] !== observedStore.test) { t0 = <div>{observedStore.test}</div>; $[0] = observedStore.test; $[1] = t0; } else { t0 = $[1]; } return t0; }; return Cmp; } function _temp() { return store; } ``` ### How often does this bug happen? Every time ### What version of React are you using? 19 ### What version of React Com…