feat: implement channel runtime connectors

app-instance/backend/beaver/interfaces/channels/manager.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import asyncio
+from collections.abc import Awaitable, Callable
 from contextlib import suppress
 
 from beaver.foundation.events import MessageBus, OutboundMessage
@@ -20,13 +21,17 @@ class ChannelManager:
         self.started = False
 
     def register(self, channel: ChannelAdapter) -> None:
-        if self.started:
-            raise RuntimeError("Cannot register channels after ChannelManager.start()")
-        if channel.name in self.channels:
-            raise ValueError(f"Channel already registered: {channel.name}")
-        if channel.bus is not self.bus:
-            raise ValueError("Channel must share the same MessageBus as ChannelManager")
-        self.channels[channel.name] = channel
+        if channel.channel_id in self.channels:
+            raise ValueError(f"Channel already registered: {channel.channel_id}")
+        self.channels[channel.channel_id] = channel
+
+    def unregister(self, channel_id: str) -> ChannelAdapter | None:
+        return self.channels.pop(channel_id, None)
+
+    def replace_registered(self, channel: ChannelAdapter) -> ChannelAdapter | None:
+        old = self.channels.get(channel.channel_id)
+        self.channels[channel.channel_id] = channel
+        return old
 
     async def start(self) -> None:
         started: list[ChannelAdapter] = []
@@ -53,7 +58,13 @@ class ChannelManager:
         if errors:
             raise RuntimeError(f"Failed to stop {len(errors)} channel(s)") from errors[0]
 
-    async def dispatch_outbound(self, stop_event: asyncio.Event) -> None:
+    async def dispatch_outbound(
+        self,
+        stop_event: asyncio.Event,
+        *,
+        on_delivered: Callable[[OutboundMessage], Awaitable[None]] | None = None,
+        on_failed: Callable[[OutboundMessage, Exception | None], Awaitable[None]] | None = None,
+    ) -> None:
         """Route bus outbound messages until stopped and the queue is drained."""
 
         while True:
@@ -68,9 +79,16 @@ class ChannelManager:
             channel = self.channels.get(message.channel)
             if channel is None:
                 self.undeliverable.append(message)
+                if on_failed is not None:
+                    await on_failed(message, None)
                 continue
 
             try:
                 await channel.send(message)
-            except Exception:  # pragma: no cover - defensive channel isolation
+            except Exception as exc:  # pragma: no cover - defensive channel isolation
                 self.undeliverable.append(message)
+                if on_failed is not None:
+                    await on_failed(message, exc)
+            else:
+                if on_delivered is not None:
+                    await on_delivered(message)