feat(mcp-tool): wire McpToolService into deploy stack

Three pieces, all required for an end-to-end MCP tool call:

* McpToolService used generic spec names "request"/"response" instead of
  "mcp-tool-request"/"mcp-tool-response", so RequestResponseSpec's
  flow-config topic lookup never matched and consumers bound to literal
  subjects nobody else publishes to.

* Add entrypoints/mcp-tool.mjs (mirrors agent/librarian entrypoints) so
  the service can be launched in the prebuilt trustgraph-ts image.

* Add a `mcp-tool` service block to deploy/docker-compose.yml.

With these three fixes plus a `mcp-tool-request`/`mcp-tool-response`
entry in each flow's topics map, the agent ReAct loop can now invoke
remote MCP tools (verified end-to-end against Brave Search and FireCrawl).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

ts/deploy/docker-compose.yml

@@ -298,6 +298,18 @@ services:
       - trustgraph
     restart: unless-stopped
 
+  mcp-tool:
+    image: trustgraph-ts:local
+    command: ["node", "entrypoints/mcp-tool.mjs"]
+    environment:
+      - NATS_URL=nats://nats:4222
+    depends_on:
+      nats:
+        condition: service_healthy
+    networks:
+      - trustgraph
+    restart: unless-stopped
+
   librarian:
     image: trustgraph-ts:local
     command: ["node", "entrypoints/librarian.mjs"]

ts/entrypoints/mcp-tool.mjs

@@ -0,0 +1,6 @@
+import("../packages/flow/dist/agent/mcp-tool/service.js")
+  .then((m) => m.McpToolService.launch("mcp-tool"))
+  .catch((err) => {
+    console.error(err);
+    process.exit(1);
+  });

ts/packages/flow/src/agent/mcp-tool/service.ts

@@ -36,9 +36,9 @@ export class McpToolService extends FlowProcessor {
     super(config);
 
     this.registerSpecification(
-      new ConsumerSpec<ToolRequest>("request", this.onRequest.bind(this)),
+      new ConsumerSpec<ToolRequest>("mcp-tool-request", this.onRequest.bind(this)),
     );
-    this.registerSpecification(new ProducerSpec<ToolResponse>("response"));
+    this.registerSpecification(new ProducerSpec<ToolResponse>("mcp-tool-response"));
 
     this.registerConfigHandler(this.onMcpConfig.bind(this));
   }
@@ -79,7 +79,7 @@ export class McpToolService extends FlowProcessor {
     const requestId = properties.id;
     if (!requestId) return;
 
-    const responseProducer = flowCtx.flow.producer<ToolResponse>("response");
+    const responseProducer = flowCtx.flow.producer<ToolResponse>("mcp-tool-response");
 
     try {
       const result = await this.invokeTool(