refactor(web): set up component test infra + decompose ProjectWizard

Phase 4a: Add @testing-library/react, user-event, jest-dom, jsdom.
Switch vitest environment to jsdom, add setup file, create test-utils
with QueryClient wrapper.

Phase 4b: Extract ProjectWizard form logic into project-wizard/ subdir:
- types.ts: WizardState, Assignment, constants, factory functions
- useProjectWizardForm.ts: form state hook + canGoNext pure function

Phase 4c: 32 tests for canGoNext validation (all 5 steps), makeDefaultState,
and makeReq factory function.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/vitest.config.mts

@@ -8,8 +8,9 @@ export default defineConfig({
     },
   },
   test: {
-    environment: "node",
+    environment: "jsdom",
     include: ["src/**/*.{test,spec}.{ts,tsx}"],
+    setupFiles: ["./src/vitest-setup.ts"],
     coverage: {
       provider: "v8",
       reporter: ["text", "lcov"],