Fix React import to work with esModuleInterop: false (#1946)

## Summary

Fixes TypeScript compilation error in
`tests/registerServerComponent.client.test.jsx` by changing React
imports from default import syntax to namespace import syntax.

**Changes:**
- Updated `RSCRoute.tsx` to use `import * as React from 'react'`
- Updated `RSCProvider.tsx` to use `import * as React from 'react'`

**Root Cause:**
The project's `tsconfig.json` has `esModuleInterop: false`, but
`@types/react` uses `export =` syntax. This combination requires
namespace imports (`import * as React`) rather than default imports
(`import React`).

**Before:**
```typescript
import React, { Component, use, type ReactNode } from 'react';
```

**After:**
```typescript
import * as React from 'react';
import { Component, use, type ReactNode } from 'react';
```

## Test Plan

- [x] Verified `tests/registerServerComponent.client.test.jsx` now
passes
- [x] Ran all non-RSC tests in react-on-rails-pro package - all passing
- [x] Ran linting checks (ESLint, Prettier, RuboCop) - all passing
- [x] Pre-commit hooks passed automatically

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Refactor**
* Internal code organization improvements with no changes to user-facing
functionality or behavior.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Co-authored-by: Claude <noreply@anthropic.com>

Author: justin808

packages/react-on-rails-pro/src/RSCProvider.tsx

@@ -14,7 +14,8 @@
 
 'use client';
 
-import React, { createContext, useContext, type ReactNode } from 'react';
+import * as React from 'react';
+import { createContext, useContext, type ReactNode } from 'react';
 import type { ClientGetReactServerComponentProps } from './getReactServerComponent.client.ts';
 import { createRSCPayloadKey } from './utils.ts';
 

packages/react-on-rails-pro/src/RSCRoute.tsx

@@ -16,7 +16,8 @@
 
 'use client';
 
-import React, { Component, use, type ReactNode } from 'react';
+import * as React from 'react';
+import { Component, use, type ReactNode } from 'react';
 import { useRSC } from './RSCProvider.tsx';
 import { ServerComponentFetchError } from './ServerComponentFetchError.ts';