Fix TypeScript type definitions for test suite

- Add explicit Describe and It interfaces with todo support
- Fix mock type compatibility in jest.ts
- Update import assertions to import attributes (assert -> with)
- Add dynamic.d.mts declaration file
- Fix spec files to use explicit type declarations

packages/dev-test/tsconfig.spec.json

@@ -8,7 +8,8 @@
     "noEmit": true
   },
   "include": [
-    "src/**/*.spec.ts"
+    "src/**/*.spec.ts",
+    "src/globals.d.ts"
   ],
   "references": [
     { "path": "../dev-test/tsconfig.build.json" }