api: drop the ILogosDelivery interface and its module

LogosDelivery is the top of the layering and nothing abstracts over it (the
FFI holds the concrete FFIContext[LogosDelivery]), so the ILogosDelivery RootObj
base bought nothing: its `method`s only returned "not implemented" and were
never dispatched. Remove the interface, keep LogosDelivery as a plain object,
and demote its start/stop/isOnline from `method` to `proc` (static dispatch on
the concrete type).

That left `api/logos_delivery_api.nim` holding only EventConnectionStatusChange.
Move it to `waku/api/events/health_events.nim` -- alongside the sibling topic
health events and next to its emitter (the health monitor, which already imported
that module) -- and delete the now-empty `logos_delivery_api.nim`.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

logos_delivery/api/logos_delivery_api.nim

@@ -1,33 +0,0 @@
-## `LogosDelivery` is the project entry point. It is a pure concentrator: it
-## owns exactly one instance of each API layer
-##
-##   Waku  <-  MessagingClient  <-  ReliableChannelManager
-##
-## and chains them together (each layer drives the one below it). Every layer
-## keeps its own, separate public API — `LogosDelivery` only wires them up and
-## drives the shared `new` / `start` / `stop` lifecycle.
-
-{.push raises: [].}
-
-import results, chronos
-import brokers/event_broker
-import types as api_types
-
-export api_types, event_broker
-
-type
-  ## Entry point. Holds one instance of each API layer.
-  ILogosDelivery* = ref object of RootObj
-
-EventBroker:
-  type EventConnectionStatusChange* = object
-    connectionStatus*: ConnectionStatus
-
-method start*(self: ILogosDelivery): Future[Result[void, string]] {.async, base.} =
-  return err("ILogosDelivery.start not implemented")
-
-method stop*(self: ILogosDelivery): Future[Result[void, string]] {.async, base.} =
-  return err("ILogosDelivery.stop not implemented")
-
-method isOnline*(self: ILogosDelivery): Future[Result[bool, string]] {.async, base.} =
-  return err("ILogosDelivery.isOnline not implemented")

logos_delivery/logos_delivery.nim

@@ -11,9 +11,6 @@
 
 import results, chronos, chronicles
 
-import logos_delivery/api/logos_delivery_api
-export logos_delivery_api
-
 # Each layer has a core module (type + new/start/stop) and an api/ folder whose
 # modules each implement a differentiated set of operations, plus an events
 # surface. The concentrator re-exports them so library consumers get the full
@@ -75,7 +72,7 @@ type
     messaging*: MessagingClientConf
     reliableChannel*: ReliableChannelManagerConf
 
-  LogosDelivery* = ref object of ILogosDelivery
+  LogosDelivery* = ref object
     ## Entry point. Holds one instance of each API layer.
     waku*: Waku
     messagingClient*: MessagingClient
@@ -120,7 +117,7 @@ proc new*(
     )
   )
 
-method start*(self: LogosDelivery): Future[Result[void, string]] {.async.} =
+proc start*(self: LogosDelivery): Future[Result[void, string]] {.async.} =
   ## Starts each layer bottom-up: transport first, then messaging, then channels.
   if self.waku.isNil():
     return err("Waku node is not initialized")
@@ -140,7 +137,7 @@ method start*(self: LogosDelivery): Future[Result[void, string]] {.async.} =
 
   return ok()
 
-method stop*(self: LogosDelivery): Future[Result[void, string]] {.async.} =
+proc stop*(self: LogosDelivery): Future[Result[void, string]] {.async.} =
   ## Stops in reverse order so higher layers drain before their dependencies.
   await self.reliableChannelManager.stop()
   await self.messagingClient.stop()
@@ -150,7 +147,7 @@ method stop*(self: LogosDelivery): Future[Result[void, string]] {.async.} =
 
   return ok()
 
-method isOnline*(self: LogosDelivery): Future[Result[bool, string]] {.async.} =
+proc isOnline*(self: LogosDelivery): Future[Result[bool, string]] {.async.} =
   if self.waku.isNil():
     return err("Waku node is not initialized")
   return ok(self.waku.healthMonitor.onlineMonitor.amIOnline())

logos_delivery/messaging/delivery_service/recv_service/recv_service.nim

@@ -13,7 +13,7 @@ import
 import
   logos_delivery/api/kernel_api, # MessageSeenEvent
   logos_delivery/api/messaging_client_api, # MessageReceivedEvent
-  logos_delivery/api/logos_delivery_api # EventConnectionStatusChange
+  logos_delivery/waku/api/events/health_events # EventConnectionStatusChange
 
 const MaxMessageLife = chronos.minutes(7) ## Max time we will keep track of rx messages
 

logos_delivery/waku/api/events/health_events.nim

@@ -4,10 +4,12 @@ import logos_delivery/api/types
 import logos_delivery/waku/node/health_monitor/[protocol_health, topic_health]
 import logos_delivery/waku/waku_core/topics
 
-export protocol_health, topic_health
+export event_broker, protocol_health, topic_health
 
-# Note: `EventConnectionStatusChange` lives in `logos_delivery/api/logos_delivery_api`
-# (the top-level orchestrator interface owns the node-connectivity event).
+# Emitted by the health monitor when overall node connectivity changes.
+EventBroker:
+  type EventConnectionStatusChange* = object
+    connectionStatus*: ConnectionStatus
 
 # Notify health changes to a subscribed topic
 # TODO: emit content topic health change events when subscribe/unsubscribe

logos_delivery/waku/node/health_monitor/node_health_monitor.nim

@@ -9,7 +9,6 @@ import
   libp2p/protocols/pubsub,
   libp2p/protocols/pubsub/rpc/messages,
   logos_delivery/api/types,
-  logos_delivery/api/logos_delivery_api, # EventConnectionStatusChange
   logos_delivery/waku/[
     waku_relay,
     waku_rln_relay,