Refactor: Derive consumer behaviour from queue class (#772)

Derive consumer behaviour from queue class, remove
consumer_type parameter

The queue class prefix (flow, request, response, notify) now
fully determines consumer behaviour in both RabbitMQ and Pulsar
backends.  Added 'notify' class for ephemeral broadcast (config
push notifications).  Response and notify classes always create
per-subscriber auto-delete queues, eliminating orphaned queues
that accumulated on service restarts.

Change init-trustgraph to set up the 'notify' namespace in
Pulsar instead of old hangover 'state'.

Fixes 'stuck backlog' on RabbitMQ config notification queue.

trustgraph-base/trustgraph/schema/core/topic.py

@@ -6,10 +6,10 @@ def queue(topic, cls='flow', topicspace='tg'):
     Args:
         topic: The logical queue name (e.g. 'config', 'librarian')
         cls: Queue class determining operational characteristics:
-             - 'flow' = persistent processing pipeline queue
-             - 'request' = non-persistent, short TTL request queue
-             - 'response' = non-persistent, short TTL response queue
-             - 'state' = persistent, last-value state broadcast
+             - 'flow' = persistent shared work queue (competing consumers)
+             - 'request' = non-persistent RPC request queue (shared)
+             - 'response' = non-persistent RPC response queue (per-subscriber)
+             - 'notify' = ephemeral broadcast (per-subscriber, auto-delete)
         topicspace: Deployment isolation prefix (default: 'tg')
 
     Returns:
@@ -20,7 +20,7 @@ def queue(topic, cls='flow', topicspace='tg'):
             # flow:tg:text-completion-request
         queue('config', cls='request')
             # request:tg:config
-        queue('config', cls='state')
-            # state:tg:config
+        queue('config', cls='notify')
+            # notify:tg:config
     """
     return f"{cls}:{topicspace}:{topic}"

trustgraph-base/trustgraph/schema/services/config.py

@@ -62,7 +62,7 @@ class ConfigPush:
 
 config_request_queue = queue('config', cls='request')
 config_response_queue = queue('config', cls='response')
-config_push_queue = queue('config', cls='flow')
+config_push_queue = queue('config', cls='notify')
 
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