edge: D2D parity for peer lifecycle @on handlers

[soupat]

Summary

• Deliver @on(event_name="peer_present"|"peer_lost") handlers via PresenceCollector callbacks when a D2D collector is present, so D2D drivers see the same lifecycle events as registry-mode drivers (which already get them through edge: support lifecycle event subscriptions and glob device_id filters #27's broker subject).
• PresenceCollector gains symmetric on_peer_removed support and a multi-listener model (back-compat with the existing collector._on_new_peer = ... pattern in device.py).
• 9 new tests; existing @on and registry-mode behavior unchanged.

Background

This is the rebased content of PR #31, which was merged into the now-orphaned stacked base branch feat/peer-lifecycle-events after #27 squash-merged to main first. The diff against main is the same 390 LOC as before.

How

discovery.py:

• PresenceCollector grows symmetric on_peer_removed support (fires on departing: true graceful departure AND on prune-timeout in _prune_loop).
• Multi-listener model: constructor-form on_new_peer / on_peer_removed kwargs still work as single-listener seeds; new add_on_new_peer / add_on_peer_removed methods append additional listeners. The existing collector._on_new_peer = ... pattern in device.py keeps working via a back-compat property.

drivers/base.py:

• _setup_subscription checks self._device._d2d_collector for lifecycle aliases; if present, the handler is wired via the collector's new listener methods (_setup_lifecycle_d2d) instead of subscribing to the broker subject.
• Per-device events are unaffected; still subscribe through the broker.

Glob and exact device_id= filters apply post-hoc inside the delivery wrapper (same _device_id_matches helper as #27).

Tests

9 new tests:

TestLifecycleSubscriptionsD2D
  test_peer_lost_routes_through_collector
  test_peer_present_routes_through_collector
  test_d2d_lifecycle_device_id_filter_exact
  test_d2d_lifecycle_device_id_filter_glob
  test_d2d_per_device_event_still_uses_broker

TestPresenceCollectorRemovedCallback
  test_graceful_departure_fires_on_peer_removed
  test_prune_timeout_fires_on_peer_removed
  test_add_on_peer_removed_supports_multiple_listeners
  test_constructor_callback_coexists_with_listeners

Test plan

• Edge unit tests pass
• Integration suite passes (note: tests: fix flaky test_multiple_sensors[zenoh] #32 fixes a separate pre-existing zenoh discovery flake that surfaced on the edge: support lifecycle event subscriptions and glob device_id filters #27 merge)

[soupat]

this was reviewed and merged but not on the main.