There's a desire to support a persistent model for some executables (initially just the Aspire dashboard) that would allow a given executable to survive DCP runs.

We'll need to expand our existing persistent storage implementation to allow for tracking the PID/start time of a given process using a well known key (similar to how a container name is used to identify a persistent container). We'll also want to calculate and store a lifecycle key like we do for containers so that we can detect material changes to a persistent executable between runs and recreate if necessary.

We should also allow an additional "session" PID to be specified that can be used to terminate persistent executables (for example the PID for dotnet watch). This PID would be passed to the dcpproc instance for a persistent executable and ensure it is cleaned up properly once the larger session is complete. This would differentiate the persistent executable and persistent container behavior.