feat(core,cli): enforce mandatory MessageBus injection (Phase 3 Hard Migration) (#15776)

packages/core/src/config/config.test.ts

@@ -61,7 +61,6 @@ vi.mock('../tools/tool-registry', () => {
   ToolRegistryMock.prototype.sortTools = vi.fn();
   ToolRegistryMock.prototype.getAllTools = vi.fn(() => []); // Mock methods if needed
   ToolRegistryMock.prototype.getTool = vi.fn();
-  ToolRegistryMock.prototype.setMessageBus = vi.fn();
   ToolRegistryMock.prototype.getFunctionDeclarations = vi.fn(() => []);
   return { ToolRegistry: ToolRegistryMock };
 });

packages/core/src/config/config.ts

@@ -1633,10 +1633,7 @@ export class Config {
   }
 
   async createToolRegistry(): Promise<ToolRegistry> {
-    const registry = new ToolRegistry(this);
-
-    // Set message bus on tool registry before discovery so MCP tools can access it
-    registry.setMessageBus(this.messageBus);
+    const registry = new ToolRegistry(this, this.messageBus);
 
     // helper to create & register core tools that are enabled
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
@@ -1659,9 +1656,7 @@ export class Config {
       }
 
       if (isEnabled) {
-        // Pass message bus to tools when feature flag is enabled
-        // This first implementation is only focused on the general case of
-        // the tool registry.
+        // Pass message bus to tools (required for policy engine integration)
         const toolArgs = [...args, this.getMessageBus()];
 
         registry.registerTool(new ToolClass(...toolArgs));