ng serve with esbuild/Vite ignores sourceMap configuration, injecting large inline source maps into all files

### Command

serve

### Is this a regression?

- [ ] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

_No response_

### Description

The development server (ng serve), which uses Vite/esbuild, consistently injects large, inline Base64 source maps into every JavaScript file it serves.

This behavior occurs even when source maps are explicitly disabled in angular.json and/or tsconfig.json. The most problematic aspect is that this transformation is also applied to pre-built, third-party packages from node_modules.

This unnecessarily inflates file sizes (often by 2-3x), which slows down page loads in development and makes debugging in browser DevTools more difficult due to the massive file content. The core issue is that the configuration to disable this behavior is not being respected.

### Minimal Reproduction

1. Create a new Angular project:
```bash
ng new sourcemap-repro
cd sourcemap-repro
```
2. In `angular.json`, modify the configuration for the development server to explicitly disable all source maps. Under `projects.sourcemap-repro.architect.build.configurations.development`, set the `sourceMap` option:
```json
"sourceMap": false
```
*(Alternatively, using a more granular object like `{"scripts": false, "styles": false, "vendor": false}` also fails to prevent the issue.)*

3. Run the development server:
```bash
ng serve
```
4. Open the application in a browser and launch the developer tools (e.g., Chrome DevTools).
5. Navigate to the "Network" tab, refresh the page, and inspect any `.js` file (e.g., `main.js`, `polyfills.js`, or a chunk from `@angular/core`).
6. View the "Response" or "Source" for that file.

**Expected Behavior:**
The served JavaScript files should **not** contain an inline source map. The file should end without a `//# sourceMappingURL=...` comment.

**Actual Behavior:**
Every JavaScript file has a large inline Base64 source map appended to it, directly contradicting the configuration in `angular.json`.

### Exception or Error

```text

```

### Your Environment

```text
Angular CLI: 19.2.14
Node: 20.19.0
Package Manager: npm 10.8.2
OS: darwin arm64

Angular: undefined
...

Package Version
---------------------------------------------------------
@angular-devkit/architect 0.1902.15
@angular-devkit/build-angular 19.2.14
@angular-devkit/core 19.2.14
@angular-devkit/schematics 19.2.14
@angular/cli 19.2.14
@angular/compiler 19.2.14
@angular/compiler-cli 19.2.14
@angular/language-service 19.2.14
@schematics/angular 18.2.11
ng-packagr 18.2.1
typescript 5.7.2
zone.js 0.15.0
```

### Anything else relevant?

ng new、angular.json、tsconfig.json、ng serve を使って問題を再現し、その後、ブラウザーのネットワークツールで配信された JavaScript を調べます。Vite/esbuild の開発サーバーパスが sourceMap 設定をどのように処理するかを追跡します。sourceMap false によってアプリケーションおよび node_modules の JavaScript ファイル内のインライン Base64 マップが防止されれば完了です。

索引モデルが issue の本文から書いたものです。