* feat: add runtime vm cache sync
* feat: configure runtime vm cache sync
* feat: prefetch vm cache on startup
* feat: await vm cache before vm startup
* fix: recheck vm cache after prefetch wait
* fix: address vm cache review feedback
* build(server): require VM cache manifest env
The --compile-only and --ci flags served overlapping purposes for CI
builds. Remove --compile-only entirely since --ci already handles the
CI use case (skip R2, skip prod env validation, local zip packaging)
and --no-upload covers the upload-skipping use case for full builds.
Add a compile-only mode to the server build pipeline for CI/CD
environments that don't have R2 credentials. The --compile-only flag
skips resource staging and upload, producing only compiled binaries.
