test(delegate-task): update isPlanAgent test for exact match fix

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/tools/delegate-task/tools.test.ts

@@ -180,8 +180,8 @@ describe("sisyphus-task", () => {
       //#given / #when
       const result = isPlanAgent("planner")
 
-      //#then - "planner" contains "plan" so it matches via includes
-      expect(result).toBe(true)
+      //#then - "planner" is NOT an exact match for "plan" (T37 exact match fix)
+      expect(result).toBe(false)
     })
 
     test("returns true for case-insensitive match 'PLAN'", () => {