bug: incompatible value of this used for getters/setters during SSR hydration

[kyleMessnerLillyContractor]

Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already report this problem, without success.

Stencil Version

4.43.5

Current Behavior

The following code produces a type error

@Prop()
get value(): number {
  return this.internalValue;
}
set value(newValue: number) {
  this.internalValue = this.formatValue(value);
}

This line

core/src/hydrate/platform/proxy-host-element.ts

Line 77 in 06258c8

origSetter.apply(elm, [attrPropVal]);

calls apply with the proxy host element which, in the examples case, does not have a reference for this.formatValue. The result is that the setter tries to execute undefined like a function. This error seems to result in elements hydrating with templates that have nothing from the component's render method.

Expected Behavior

Referencing things on the this object does not result in in SSR hydration producing incorrect template HTML

System Info

System: node 22.22.3
    Platform: darwin (25.5.0)
   CPU Model: Apple M4 Pro (12 cpus)
    Compiler: /Users/***/***/node_modules/.pnpm/@stencil+core@4.43.5/node_modules/@stencil/core/compiler/stencil.js
       Build: 1779994050
     Stencil: 4.43.5 🍐
  TypeScript: 5.8.3
      Rollup: 4.44.0
      Parse5: 7.2.1
      jQuery: 4.0.0-pre
      Terser: 5.37.0

Steps to Reproduce

@Prop()
get value(): number {
  return this.internalValue;
}
set value(newValue: number) {
  this.internalValue = this.formatValue(value);
}

then render it using the @stencil/ssr hydrate module and check the response back from the server.

Code Reproduction URL

n/a

Additional Information

No response