refactor(form): migrate useForm to TypeScript store

Replaces useForm.svelte.ts with useForm.ts, refactoring the form logic to use Svelte stores and TypeScript interfaces. Updates imports in Form.svelte and index.ts to use the new implementation. This change improves type safety, reactivity, and maintainability of the form handling logic.

Author: brodienguyen

packages/svelte5/src/components/Form.svelte

@@ -9,9 +9,9 @@
     type VisitOptions,
     isUrlMethodPair,
   } from '@inertiajs/core'
+  import useForm from '../useForm'
   import { isEqual } from 'lodash-es'
   import { onMount } from 'svelte'
-  import useForm from '../useForm.svelte'
 
   const noop = () => undefined
 

packages/svelte5/src/index.ts

@@ -7,7 +7,7 @@ export { default as createInertiaApp } from './createInertiaApp'
 export { default as inertia } from './link'
 export { default as page } from './page'
 export { type ResolvedComponent } from './types'
-export { default as useForm, type InertiaFormRunes, type InertiaFormProps } from './useForm.svelte'
+export { default as useForm, type InertiaForm, type InertiaFormProps } from './useForm'
 export { default as usePoll } from './usePoll'
 export { default as usePrefetch } from './usePrefetch'
 export { default as useRemember } from './useRemember'