Allow using `vi.mock` (and related) functions in tests

### Which @angular/* package(s) are relevant/related to the feature request?

core

### Description

With the new Angular unit-test builder (Vite), test files are bundled into unified chunks.
Because of this full bundling step:

- ESM modules are statically linked at build time
- There is no runtime module graph available
- vi.mock() cannot intercept module loading
- Mocking entire modules (components/services/modules) is not possible

Currently if we use `vi.mock` function for automocking component/directives/services/pipes/etc..., we got an error:

```
Error: The "vi.mock" and related methods are not supported with the Angular unit-test system. Please use Angular TestBed for mocking.
```

TestBed overrides are insufficient because:

- They replace Angular metadata (providers/imports), not module implementation
- They cannot replace pure TS logic or side effects
- They do not intercept ESM import bindings

### Proposed solution

Instead of runtime interception (like Vitest normally does), Angular test builder should:

1. Detect `vi.mock()` calls at compile time (in spec files, and in setupFiles)
2. Hoist them
3. Rewrite import bindings to use a generated mock registry
4. Replace module resolution during bundling

I suggest to create esbuild plugin, that:

1. Parse test file AST
2. Detect:
- `vi.mock()`
- `vi.unmock()`
- `vi.doMock()`
- `vi.doUnmock()`
- `vi.importMock()`
- `vi.importActual()`
- `vi.hoisted()`
3. Hoist mock calls
4. Rewrite imports

#### Example Transform Injectable

**Before**:
```typescript
import { MyService } from './my-service';
import { MyOtherService } from './my-other-service';

vi.mock('./my-service', () => ({
MyService:
@Injectable({providedIn: 'root'})
class {
get() { return 'mock'; }
}
}));

vi.mock('./my-other-service');

test(() => {
const myService = new MyService();
const myOtherService = new MyOtherService();
});
```

**After**:
```typescript
// should initialize once in one environment
const __angularViMocks = (globalThis.__angular_vi_mocks ??= new Map());

__angularViMocks.set(
'./my-service',
(() => ({
MyService: class {
get() { return 'mock'; }
static ɵprov = {
providedIn: 'root',
factory: () => new this();
};
static ɵfac = () => new this();
}
}))()
);

__angularViMocks.set(
'./my-other-service',
(() => ({
MyOtherService: class {
get = vi.fn(); // maybe better to put `vi.fn()` to MyOtherService.prototype.get = vi.fn();
static ɵprov = {
providedIn: 'root',
factory: () => new this();
};
static ɵfac = () => new this();
}
}))()
);

import * as __angularViActualMod1 from './my-service';
import * as __angularViActualMod2 from './my-other-service';

// We should replace that import in every dependent chunk.
const { MyService } = __angularViMocks.get('./my-service') ?? __angularViActualMod1;
const { MyOtherService } = __angularViMocks.get('./my-other-service') ?? __angularViActualMod2;
```

### Requirements:

- Must mock full implementation (not only metadata) for any modules, as `vi.mock()` does
- Must stub components, services, modules, pipes, directives both metadata and implementation
- Must preserve ESM live bindings semantics
- Must preserve sourcemaps and coverage
- Must not require runtime module loader

### Alternatives considered

Currently we have no choice, but stay with slow and inefficient `jest` + `jest-preset-angular`.

I've implemented deep-automocking infrastructure for `jest.mock()` [ng-automocks-jest](https://www.npmjs.com/package/ng-automocks-jest), it can stub any angular entities, both metadata and implementation.

Start with the new Angular unit-test builder and its Vite bundling path, then trace where vi.mock calls are rejected and how spec files and setupFiles are transformed. Review the proposed compile-time detection, hoisting, import rewriting, and mock registry requirements. Done means supporting the listed vi functions while preserving ESM live bindings, sourcemaps, coverage, and no runtime module loader.

Written by the indexing model from the issue text.