RabbitMQ fixes: thread safety, subscriber resilience, config errors

Consumer thread safety:
- Dedicated ThreadPoolExecutor per consumer so all pika operations
  (create, receive, acknowledge, negative_acknowledge) run on the
  same thread — pika BlockingConnection is not thread-safe
- Applies to both Consumer and Subscriber classes

Subscriber resilience:
- Move consumer creation from start() into the run() loop so it is
  recreated after connection failures instead of spinning on None

Config handler type audit — fix four mismatched type registrations:
- librarian: was ["librarian"] (non-existent type), now ["flow",
  "active-flow"] (matches config["flow"] that the handler reads)
- cores/service: was ["kg-core"], now ["flow"] (reads
  config["flow"])
- metering/counter: was ["token-costs"], now ["token-cost"]
  (singular)
- agent/mcp_tool: was ["mcp-tool"], now ["mcp"] (reads
  config["mcp"])

Update tests

trustgraph-flow/trustgraph/agent/mcp_tool/service.py

@@ -24,7 +24,7 @@ class Service(ToolService):
             **params
         )
 
-        self.register_config_handler(self.on_mcp_config, types=["mcp-tool"])
+        self.register_config_handler(self.on_mcp_config, types=["mcp"])
 
         self.mcp_services = {}
 

trustgraph-flow/trustgraph/cores/service.py

@@ -108,7 +108,7 @@ class Processor(AsyncProcessor):
             flow_config = self,
         )
 
-        self.register_config_handler(self.on_knowledge_config, types=["kg-core"])
+        self.register_config_handler(self.on_knowledge_config, types=["flow"])
 
         self.flows = {}
 

trustgraph-flow/trustgraph/librarian/service.py

@@ -246,7 +246,10 @@ class Processor(AsyncProcessor):
             taskgroup = self.taskgroup,
         )
 
-        self.register_config_handler(self.on_librarian_config, types=["librarian"])
+        self.register_config_handler(
+            self.on_librarian_config,
+            types=["flow", "active-flow"],
+        )
 
         self.flows = {}
 

trustgraph-flow/trustgraph/metering/counter.py

@@ -40,7 +40,7 @@ class Processor(FlowProcessor):
             }
         )
 
-        self.register_config_handler(self.on_cost_config, types=["token-costs"])
+        self.register_config_handler(self.on_cost_config, types=["token-cost"])
 
         self.register_specification(
             ConsumerSpec(