Replace the eventfd/ring job bootstrap with one inherited arena descriptor, actor-owned sessions, sealed blob leases, awaitable inbox wakeups, and zero-copy Python mappings. Route VastAI mock provisioning through image-backed local Docker workers and preserve pinned child and controller routes across directory updates.
Add TOML job-file submission to the Fleet UI with generic started, running, and completed feedback, reusable remote job controller routing, cancellation and kill invariants, Tinygrad fixture and image support, and comprehensive Rust, Python, CUDA, and lifecycle-ordering coverage.
