Svelte form - `state_proxy_equality_mismatch` warnings when calling `field.handleChange()`

Describe the bug

Each call to field.handleChange() generates multiple state_proxy_equality_mismatch svelte warning in console.

Your minimal, reproducible example

https://codesandbox.io/p/devbox/github/tanstack/form/tree/main/examples/svelte/simple?embed=1&theme=dark&file=src/App.svelte

Steps to reproduce

1. Open the simple example for svelte form - https://codesandbox.io/p/devbox/github/tanstack/form/tree/main/examples/svelte/simple?embed=1&theme=dark&file=src/App.svelte
2. Open devtools console
3. Type anything into first name
4. Each keystroke generates 7 state_proxy_equality_mismatch warnings in console.

Reactive `$state(...)` proxies and the values they proxy have different identities. Because of this, comparisons with `===` will produce unexpected results

Expected behavior

I expect no warning to be in console.

How often does this bug happen?

Every time

Screenshots or Videos

Platform

• Chrome 150
• Rocky Linux

TanStack Form adapter

svelte-form

TanStack Form version

1.33.2

TypeScript version

No response

Additional context

The warning appears in version 1.33.0 and up. They do not appear in version 1.32.1 and lower.

Start with the Svelte simple example at examples/svelte/simple/src/App.svelte and reproduce the issue in the linked CodeSandbox by typing in the first-name field while watching the console. Compare behavior between versions 1.32.1 and 1.33.0; done means repeated field.handleChange() calls no longer produce state_proxy_equality_mismatch warnings.