feat(frontend): convert to ts (#37)

* feat(frontend): convert to ts

* refactor(frontend): axios-override - simplify shouldMock type

* fix: refine stage labels

* refactor(frontend): refine `useUserId` signature

* fix(frontend): descriptionLines and langsCount can be undefined

* refactor(frontend): refine casting on redirectCode

* refactor(frontend): refine stageIndex title and types

* refactor(frontend): apply pr review comments changes

* refactor(frontend): group properties using reference groups

* refactor(frontend): remove outdated comment

* fix(frontend): mock-http - simplify code

.github/workflows/ci.yml

@@ -72,3 +72,6 @@ jobs:
 
       - name: Lint (knip)
         run: pnpm run lint:knip
+
+      - name: Typecheck
+        run: pnpm run typecheck