chore(lint): burn down remaining warnings to zero

src/agents/registry.test.ts

@@ -52,12 +52,18 @@ describe('AgentConfigRegistry', () => {
       });
 
       expect(registry.list()).toHaveLength(2);
-      const assistant = registry.get('assistant')!;
+      const assistant = registry.get('assistant');
+      if (!assistant) {
+        throw new Error('Expected assistant config');
+      }
       expect(assistant.systemPrompt).toBe('Be helpful.');
       expect(assistant.modelTier).toBe('default');
       expect(assistant.toolProfile).toBe('messaging');
 
-      const coder = registry.get('coder')!;
+      const coder = registry.get('coder');
+      if (!coder) {
+        throw new Error('Expected coder config');
+      }
       expect(coder.sandbox).toBe(true);
     });
   });