v0.98.6

Added

• Role-based addressing: an identity can answer to one or more <project>/<role> roles in
  addition to its instance name, so a directed message to a role (for example
  SYNAPSE-CHANNEL/coordinator) reaches whichever instance currently holds it. A waiter,
  the arm keeper, and the relay-log inbox (synapse relay --for) take a repeatable
  --role <project>/<role>; the waiter wakes and the per-agent inbox surfaces messages
  addressed to a role it holds, alongside those to its name. The addressing matchers
  (is_recipient, is_directed, wakes) gained an optional roles argument that is
  empty by default, so every existing name/project/glob match and the anti-wake-storm
  behaviour are unchanged. This closes the gap where a message addressed to a role bound to
  no instance name matched nobody — it neither woke nor inboxed the holder and was counted a
  dead letter.
• Hub-side role registry: an agent declares the roles it answers to on its registration
  heartbeat; the hub binds them (cleared on disconnect) so directed delivery resolves a role
  to whichever agents hold it. A message to a role with a live holder is no longer counted a
  dead letter (so it cannot raise a false dead-letter escalation), and the who snapshot now
  carries agent_roles showing who holds what. Roles are additive addresses, not exclusive —
  a role may be held by more than one agent and a message to it reaches every holder. The
  heartbeat roles field is parsed defensively (a non-list is ignored, non-string or blank
  entries are dropped) so a malformed field degrades to no roles rather than dropping the
  socket. Roles ride in the heartbeat payload and the who snapshot, so the wire protocol
  version, the reserved envelope keys, and the federation consumer surface are unchanged.