Model Deployment Dependency Resolution

Problem

Given a list of model packages, each package has a unique string name and a list of dependency names that must be deployed first. Implement a function that returns a valid deployment order for all packages, or an empty list if no valid order exists due to a cycle. If multiple valid orders exist, any one is acceptable.

Constraints

• 1 <= number of packages <= 10^5
• 0 <= total number of dependencies <= 2 * 10^5
• Package names are non-empty strings
• All dependency names appear as keys in packages