feat: Upgrade core dependencies and regenerate documentation (#856)

### Key Changes:

* **Dependency Upgrades:** Core packages have been updated to their
latest versions, including:
    *   `@auth0/auth0-spa-js` to `^2.2.0`
    *   `typescript` to `^5.8.3`
    *   `typedoc` to `^0.28.7`
    *   `react` and `react-dom` to `^19.1.0`
    *   Testing libraries like `jest` and `@testing-library/*`
    *   Linting tools like `@typescript-eslint/*` to `^8.x`

* **Documentation Regeneration:** As a result of the `typedoc` upgrade,
the entire `/docs` directory has been regenerated. This brings in a
modern theme, an improved structure, and new features like a hierarchy
view for better API exploration.

* **Enhanced Type Safety:** The project's `tsconfig.json` has been
configured with stricter type-checking rules, including
`exactOptionalPropertyTypes` and `noUncheckedIndexedAccess`. The
codebase has been updated to conform to these rules, leading to more
precise and safer type definitions.

* **Code Modernization:** The codebase has been refactored to use modern
JavaScript syntax, such as nullish coalescing (`??`) and optional
chaining (`?.`).

*   **Test Suite Improvements:**
* Comprehensive unit tests have been added for an internal utility
function.
* Asynchronous tests have been updated to correctly use `await act()`,
ensuring more stable and reliable test execution.

Author: subhankarmaiti

__tests__/auth-reducer.test.tsx

@@ -19,6 +19,7 @@ describe('reducer', () => {
   it('should initialise when not authenticated', async () => {
     const payload = {
       isAuthenticated: false,
+      user: undefined,
     };
     expect(
       reducer(initialAuthState, { type: 'INITIALISED', ...payload })

__tests__/utils.test.tsx

@@ -1,6 +1,31 @@
-import { hasAuthParams, loginError, tokenError } from '../src/utils';
+import { hasAuthParams, loginError, tokenError, deprecateRedirectUri } from '../src/utils';
 import { OAuthError } from '../src/errors';
 
+// Define interfaces for testing deprecateRedirectUri function
+interface TestOptionsWithRedirectUri {
+  redirectUri?: string;
+  authorizationParams?: {
+    redirect_uri?: string;
+    scope?: string;
+  };
+}
+
+interface TestOptionsWithAuthorizationParams {
+  authorizationParams: {
+    redirectUri?: string;
+    redirect_uri?: string;
+    scope?: string;
+  };
+}
+
+interface TestOptionsWithBothRedirectUri {
+  redirectUri?: string;
+  authorizationParams: {
+    scope: string;
+    redirect_uri?: string;
+  };
+}
+
 describe('utils hasAuthParams', () => {
   it('should not recognise only the code param', async () => {
     ['?code=1', '?foo=1&code=2', '?code=1&foo=2'].forEach((search) =>
@@ -62,3 +87,75 @@ describe('utils error', () => {
     }).toThrowError('Login failed');
   });
 });
+
+describe('utils deprecateRedirectUri', () => {
+  let consoleSpy: jest.SpyInstance;
+
+  beforeEach(() => {
+    consoleSpy = jest.spyOn(console, 'warn').mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    consoleSpy.mockRestore();
+  });
+
+  it('should handle options with redirectUri', () => {
+    const options: TestOptionsWithRedirectUri = {
+      redirectUri: 'https://example.com/callback',
+    };
+    
+    deprecateRedirectUri(options);
+    
+    expect(consoleSpy).toHaveBeenCalledWith(
+      'Using `redirectUri` has been deprecated, please use `authorizationParams.redirect_uri` instead as `redirectUri` will be no longer supported in a future version'
+    );
+    expect(options.authorizationParams?.redirect_uri).toBe('https://example.com/callback');
+    expect(options.redirectUri).toBeUndefined();
+  });
+
+  it('should handle options with authorizationParams.redirectUri', () => {
+    const options: TestOptionsWithAuthorizationParams = {
+      authorizationParams: {
+        redirectUri: 'https://example.com/callback',
+      },
+    };
+    
+    deprecateRedirectUri(options);
+    
+    expect(consoleSpy).toHaveBeenCalledWith(
+      'Using `authorizationParams.redirectUri` has been deprecated, please use `authorizationParams.redirect_uri` instead as `authorizationParams.redirectUri` will be removed in a future version'
+    );
+    expect(options.authorizationParams.redirect_uri).toBe('https://example.com/callback');
+    expect(options.authorizationParams.redirectUri).toBeUndefined();
+  });
+
+  it('should handle options with both redirectUri and existing authorizationParams', () => {
+    const options: TestOptionsWithBothRedirectUri = {
+      redirectUri: 'https://example.com/callback',
+      authorizationParams: {
+        scope: 'openid profile',
+      },
+    };
+    
+    deprecateRedirectUri(options);
+    
+    expect(options.authorizationParams.redirect_uri).toBe('https://example.com/callback');
+    expect(options.authorizationParams.scope).toBe('openid profile');
+    expect(options.redirectUri).toBeUndefined();
+  });
+
+  it('should handle undefined options', () => {
+    deprecateRedirectUri(undefined);
+    expect(consoleSpy).not.toHaveBeenCalled();
+  });
+
+  it('should handle options without redirectUri properties', () => {
+    const options = {
+      domain: 'example.auth0.com',
+      clientId: 'client-id',
+    };
+    
+    deprecateRedirectUri(options);
+    expect(consoleSpy).not.toHaveBeenCalled();
+  });
+});