v0.77.0

Added

• synapse debug ./hub.db --fork-at SEQ forks a task's reconstructed state at a sequence
  point: it folds the durable log back into the exact claim state the task held there — owner,
  status, declared paths, and the saved resume checkpoint — and prints the resume manifest an
  agent would pick up if the task were rewound to that point, beside the events that really
  happened next. The task is inferred from the snapshot at the sequence or named with --task,
  and --set FIELD=VALUE overrides a resume field on the manifest only. It is read-only
  inspection over the log: the hub runs no task, so nothing is executed or changed.
• synapse reproduce ./hub.db TASK fingerprints a task's authoritative history into a stable
  SHA-256 digest of its claim snapshots and releases, so the same history yields the same digest
  on every machine. --expect DIGEST gates on a known-good value and exits non-zero on any
  divergence, the way a release receipt is verified.
• synapse causality causes|effects|counterfactual ./hub.db SEQ traces coordination causality
  over the event log. It folds the durable events into a directed acyclic graph of three recorded
  relations — a task's own lifecycle, a declared depends_on satisfied by the dependency's
  completion, and a release that let a later, path-overlapping claim proceed — and answers against
  an event sequence: the events upstream of it, the events it enabled downstream, or the downstream
  events whose recorded cause traces back through it. Every edge is backed by a concrete event;
  the counterfactual is a structural what-if over the inferred graph, not statistical causal
  discovery. It is read-only and contacts no live hub.