fix: resolve all remaining test failures and improve test reliability

- Fix clear-subtasks test by implementing deep copy of mock data to prevent mutation issues between tests
- Fix add-task test by uncommenting and properly configuring generateTaskFiles call with correct parameters
- Fix analyze-task-complexity tests by properly mocking fs.writeFileSync with shared mock function
- Update test expectations to match actual function signatures and data structures
- Improve mock setup consistency across all test suites
- Ensure all tests now pass (329 total: 318 passed, 11 skipped, 0 failed)

.taskmaster/state.json

@@ -1,8 +1,8 @@
 {
-  "currentTag": "master",
-  "lastSwitched": "2025-06-14T00:46:38.351Z",
-  "branchTagMapping": {
-    "v017-adds": "v017-adds"
-  },
-  "migrationNoticeShown": true
-}
+	"currentTag": "master",
+	"lastSwitched": "2025-06-14T00:46:38.351Z",
+	"branchTagMapping": {
+		"v017-adds": "v017-adds"
+	},
+	"migrationNoticeShown": true
+}