Refs: named movable leaf pointers, one active operation per ref, parallel
under one writer. AgentRef surface implemented by AgentHarness for main;
per-ref queues, persisted config, session views, scoped watch() plus
watchSession(). Per-ref recovery and operational-log partitioning (no
parenting; log order is causal order within a ref; session entries carry
no ref, membership derives from parent linkage). Labels and session name
de-treed to global latest-wins records with setter APIs. Named
append-only context invariant (KV cache rationale for deferred writes).
New traces, API examples, and open questions for review.
Full design for the durable, resumable harness: session log with harness
entries, SessionTree query contract, public API with result unions, watch()
snapshots, events/hooks catalogs, recovery procedures as code, forks,
storage backends, and telemetry integration.
