fix: type for UseRemixFormReturn (#142)

[bravo-kernel]

Fixes type issue described in #142.

Description

UseRemixFormReturn<TFieldValues> was defined using ReturnType<typeof useRemixForm> (without passing generic parameters) to capture the overridden signatures of handleSubmit, reset, and register. Because useRemixForm is a generic function, calling ReturnType<typeof useRemixForm> without type arguments resolves it with the default TFieldValues = FieldValues, causing reset and register to be typed against the base FieldValues instead of the caller's concrete schema type.

This makes UseRemixFormReturn<ConcreteSchema> unsatisfiable in practice: the value returned by useRemixForm<ConcreteSchema>() cannot be assigned to a parameter typed as UseRemixFormReturn<ConcreteSchema> because the reset and register signatures disagree on whether the field type is FieldValues or ConcreteSchema.

The fix replaces the manual intersection with a TypeScript instantiation expression (available since TS 4.7):

// Before
UseFormReturn<TFieldValues, TContext, TTransformedValues> & {
  handleSubmit: ReturnType<typeof useRemixForm>["handleSubmit"];
  reset:        ReturnType<typeof useRemixForm>["reset"];
  register:     ReturnType<typeof useRemixForm>["register"];
}

// After
ReturnType<typeof useRemixForm<TFieldValues, TContext, TTransformedValues>>

This derives the type directly from useRemixForm's actual return, with all three generic parameters propagated correctly, while preserving the same intent: the overridden handleSubmit, reset, and register signatures are still reflected (not the base UseFormReturn ones).

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Verified by type-checking a real application against the patched build. The app calls useRemixForm<FormData>() (where FormData is a concrete Zod schema type) and passes the result to a shared helper typed as UseRemixFormReturn<FieldValues>. Before the fix this required a @ts-expect-error suppression; after the fix the helper can be made generic (UseRemixFormReturn<T>) and all errors are gone with no suppressions needed.

Steps to reproduce the original error:

import { useRemixForm, type UseRemixFormReturn } from "remix-hook-form";
import type { FieldValues } from "react-hook-form";

// Simulates a shared helper that accepts any remix form
function helper(form: UseRemixFormReturn<FieldValues>) {}

const form = useRemixForm<{ email: string }>({ ... });

helper(form); // TS2345 before fix, compiles cleanly after

• Unit tests

Checklist:

• My code follows the guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings or errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules