refactor: merge deepen-plan into ce:plan as automatic confidence check (#404)

tests/copilot-converter.test.ts

@@ -466,12 +466,12 @@ Task best-practices-researcher(topic)`
   })
 
   test("replaces colons with hyphens in slash commands", () => {
-    const input = `1. Run /deepen-plan to enhance
+    const input = `1. Run /todo-resolve to enhance
 2. Start /workflows:work to implement
 3. File at /tmp/output.md`
 
     const result = transformContentForCopilot(input)
-    expect(result).toContain("/deepen-plan")
+    expect(result).toContain("/todo-resolve")
     expect(result).toContain("/workflows-work")
     expect(result).not.toContain("/workflows:work")
     // File paths preserved