Allow passing imagetools options to `enhancedImages()`

Describe the problem

enhancedImages() builds its vite-imagetools instance internally and takes no arguments, so there is no way to scope it. Every image import carrying a query goes through imagetools, plain Vite asset queries included: import icon from "./icon.png?url&no-inline" gets decoded and re-encoded with sharp's defaults. In our repo that turns a 2,917-byte palette PNG into 5,057 bytes of truecolour.

Only ?enhanced imports are meant to be transformed — that is what defaultDirectives keys off — but the plugin is handed everything else too, and imagetools treats a non-empty query as a reason to work (JonasKruckenberg/imagetools#748). The fix offered there is imagetools({ exclude: [...] }), which can't be reached from here. The open PR against it (JonasKruckenberg/imagetools#750) only skips queries that are exactly ?url or ?raw, so ?url&no-inline would still be transformed even if it lands.

Describe the proposed solution

Let enhancedImages() accept the imagetools options it doesn't already own — exclude at minimum — and merge them with defaultDirectives and namedExports:

enhancedImages({ exclude: [/[?&](url|raw)(&|$)/] })

Alternatives considered

Skipping images whose query carries no enhanced directive, since defaultDirectives already returns nothing for them. That fixes the common case without an API change, though it leaves anyone wanting other imagetools options in the same spot.

Filtering the plugins enhancedImages() returns, in userland. Works, but it means reaching into the plugin's internals from the Vite config.

Importance

would make my life easier

Start by locating the enhancedImages() implementation and any tests covering image imports or plugin options. Trace how defaultDirectives and namedExports are passed to imagetools, then verify that caller-supplied options such as exclude are preserved and that query-only imports are handled as intended.