fix: add `experimental.forkPreloads` flag (#15135)
* feat: add `experimental.enhancedPreloading` flag
Adds a new experimental flag to gate the use of Svelte's `fork` API for
preloading. The flag defaults to `false`, disabling the fork-based
preloading behavior until explicitly enabled.
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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
* changeste
* chore: rename `enhancedPreloading` to `forkPreloads`
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>