feat: Implement CSRF protection and basic form validation, streamline form data, and add comprehensive unit and E2E tests.

tests/test_e2e.py

@@ -0,0 +1,29 @@
+import os
+import re
+import pytest
+from playwright.sync_api import Page, expect
+
+def test_homepage_has_title(page: Page):
+    page.goto("http://localhost:5000/")
+    expect(page).to_have_title(re.compile("Zeilwedstrijden"))
+
+def test_submission_flow(page: Page):
+    page.goto("http://localhost:5000/zomeravond")
+    
+    # Fill required fields
+    page.select_option("select[name='klasse']", label="Kajuitklasse")
+    page.fill("input[name='zeilnummer']", "42")
+    page.fill("input[name='bootnaam']", "Vliegende Hollander")
+    page.fill("input[name='naam']", "Hendrik Test")
+    page.fill("input[name='telefoonmobiel']", "0612345678")
+    page.fill("input[name='email']", "hendrik@example.com")
+    
+    # Accept terms
+    page.check("input#terms")
+    
+    # Submit
+    page.click("button[type='submit']")
+    
+    # Expect success redirect
+    expect(page).to_have_url(re.compile(r".*/zomeravond/success"))
+    expect(page.locator("h1")).to_have_text("Bedankt!")