fix: pass mise age key to docker run

[exKAZUu]

Summary

• pass MISE_AGE_KEY through generated docker run commands when it is defined
• keeps runtime mise decryption in entrypoints without baking the age key into images

Verification

• yarn verify

[gemini-code-assist]

Code Review

This pull request updates the start method in dockerScripts.ts to conditionally include the MISE_AGE_KEY environment variable in the docker run command if it is defined in the project environment. I have no feedback to provide.