[dvkam]

Fixes #529.

prepareDeployArtifact() drops worker.vars from the returned deployment manifest. Forward the configured vars through the existing manifest builder, matching managed CLI deployments.

Regression coverage checks configured values and empty strings, omission of missing or empty maps, assets-only output, and exclusion of dotenv and generated Wrangler vars.

Validation

• The new regression failed before the fix. All 10 artifact-preparation tests pass afterward.
• A real local build packaged through void/deploy preserves the configured vars with zero preparation fetch calls.
• Formatting, lint, builds, artifact checks, workspace typechecking, and npm/pnpm installed-package smoke checks pass.
• The full run passed 733 test files and skipped one. The Astro suite exceeded its 20-second startup limit; all 8 Astro tests passed in isolation with the original timeout.