EnvironmentService for sandboxed file systems and execution

[verdverm]

I've been pondering a concept of EnvironmentService, to be a peer of Session/Artifacts. It would be a service for providing sandboxed file systems and execution environments when needed.

• Sessions deal with events / history
• Artifacts deal with blobs
• Environments deal with filesystem/execution (think containers, edge runtimes, wasm, chroot, or other sandbox tech)
• Memory should just be a tool

I'm already prototyping something out with Dagger to inform what this might look like. Wanted to start this discussion so we can start gathering use-cases and DX opinions.

Some features I'd like to see:

• orthogonal to sessions - a session could use more than one, I could use multiple sessions against an Env
• history, snapshots, branching, forking, registry - etc (much of this is proxied Dagger capabilities, most OCI setups should support this, certainly anything BuildKit based)
• work locally or farmed out to GKE (whatever the interface is, users should be transparent to it once ADK is running, similar to artifacts)
• filesystem only vs FROM a container