v1.30.0: learned memory-value rescue in sleep consolidation (opt-in)

Added

• Learned memory-value rescue in sleep consolidation (experimental, opt-in,
  default off) (#141). With {"memoryValue":{"enabled":true}} in
  .hippo/config.json, the sleep decay pass consults the learned linear
  memory-value scorer (LC2-E2 frozen weights) before deleting a decayed
  memory: a memory ranking in the top 30% of its tenant by learned value is
  kept ("rescued") even though its strength fell below the decay threshold.
  Safety properties, all test-enforced: the scorer can only rescue, never
  delete (flag-on deletes are a strict subset of flag-off deletes); flag off
  (the default) is bit-identical to prior behavior; tenants with fewer than
  10 non-pinned memories never rescue (rank statistics are noise at tiny
  scale, and the floor prevents a condemned-only tenant from converging to an
  undeletable memory); a malformed weights constant makes flag-on sleep fail
  loudly rather than silently behave as off; memories with malformed feature
  data are never rescued and are named in a warning line. Every rescue is
  recorded in the audit log (hippo audit list --op mv_rescue) with rank
  context. Code parity with the evaluated artifact is machine-checked: the
  compiled production scorer reproduces the registered held-out retention
  0.48973684210526314 exactly (delta 0) through the benchmark harness, and a
  CI sync test pins the embedded weights to the committed artifact by value
  and digest. Caveat (from the LC2-E2 result doc): the weights' usage-feature
  signs reflect the benchmark's simulated usage, not real usage value - treat
  the flag as an experiment surface, not a recommendation.

Fixed

• MCP auto-sleep no longer risks the server process on a consolidation
  error (#141). The hippo_remember auto-sleep fired consolidate()
  without await or catch, so any consolidation failure became an unhandled
  rejection after the tool had already returned success. Errors now land as
  a logged line; the call stays fire-and-forget by design.