fix: keep CSS sourcemaps for <style> blocks in dev

[DylanPiercey]

Description

Fixes a spurious Sourcemap for "<template>.marko-virtual.scss" points to missing source files dev warning for templates with a <style> block.

The dep optimizer compiled .marko files with sourceMaps: "inline", which drops the extracted style block's separate sourcemap; the shared compiler cache then left the dev server serving the virtual CSS with no map to trace it back to the template, so the style preprocessor emitted a self-referential map to the (non-existent) virtual file. The optimizer now uses sourceMaps: "both" (retains the separate map with source content), and the entry compile configs no longer force sourceMaps: false.

Motivation and Context

Reported: templates with a <style> block emit the warning on a cold dev start. Depends on the paired compiler change (marko-js/marko#3428) so entry compiles keep CSS maps without also emitting a pointless entry-wrapper map.

Checklist:

• I have updated/added documentation affected by my changes.
• I have added tests to cover my changes.

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🦋 Changeset detected

Latest commit: d780d00

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@marko/vite	Patch

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📥 Commits

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📒 Files selected for processing (3)

• .changeset/fix-scss-virtual-sourcemap-warning.md
• src/index.ts
• src/rolldown-plugin.ts

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