fix(build): copy contract source into production image

[caiopizzol]

Moor 0.54.0 cannot start because the production image includes the contract manifest but not its runtime TypeScript source. The cron route imports that source directly, so the image exits before becoming healthy.

• Copies the internal contract package into the production stage
• Keeps the existing workspace installation and runtime import unchanged
• Restores startup without changing migrations or cron behavior

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Summary by cubic

Fixes production startup by including the contract runtime source in the final Docker image. Copies packages/contract/ so the cron route’s direct TS import resolves; no changes to migrations or cron behavior.

^{Written for commit 5e808be. Summary will update on new commits.}