When using the `file` loader (either via `loader` config or import attributes),
the `deploy-url` was not prepended to the imported file's URL in the JavaScript
output. This was because esbuild's global `publicPath` option cannot be used as
it also affects code-splitting chunk paths.

This change introduces a targeted esbuild plugin that post-processes the JS
output to prepend the publicPath (deploy-url) only to file loader asset
references, identified from the build metafile. This ensures code-splitting
chunk paths remain unaffected.

Fixes angular#32789