BUG Legacy /targets links redirect to Home instead of Target Registry

#### Describe the bug

The target-management route moved from `/targets` to `/registry/targets`, but the application does not preserve the old route as a compatibility redirect. Opening a saved `/targets` link falls through to the wildcard route and silently redirects to Home (`/`) instead of the Target Registry.

This was reproduced on commit `6fd719317c09228cb332cacf5d76b6602610b591`. Fresh searches across open issues and pull requests found no matching report. Open PR #2699 was also inspected; it does not add the missing redirect.

Relevant source: `frontend/src/App.tsx:614-625,674`.

#### Steps/Code to Reproduce

1. Start the frontend.
2. Navigate directly to `/targets`, which was the canonical target-management route before the Converter Registry change.
3. Wait for application routing to settle.
4. Observe that the URL becomes `/` and Home is displayed.

```javascript
await page.goto('/targets');
console.log(new URL(page.url()).pathname);
// Actual: '/'
// Expected: '/registry/targets'
```

#### Expected Results

The legacy `/targets` route should redirect to `/registry/targets`, preserving bookmarks, documentation links, browser history, and user intent.

For example:

```tsx
} />
```

#### Actual Results

The wildcard route redirects `/targets` to `/`. Home is shown with no explanation, and the Target Registry is not visible.

Users can recover by opening Registry manually, but existing links silently lose their destination.

#### Screenshots

N/A. The URL transition and visible Home route are deterministic from the steps above.

#### Versions

- OS: Windows
- Browser: Chromium through Playwright 1.63.0
- Node: 25.7.0
- Python: 3.14.4
- PyRIT: `1.2.0.dev0`, commit `6fd719317c09228cb332cacf5d76b6602610b591`
- Python package inventory: N/A; this is a frontend routing defect.

Inspect frontend/src/App.tsx around lines 614-625 and 674, then reproduce the routing behavior by opening /targets in the frontend or with the provided Playwright steps. Add the compatibility redirect so /targets reaches /registry/targets instead of the wildcard Home route, and verify the resulting pathname.

Written by the indexing model from the issue text.