test: update and add E2E, integration, visual, and webapp tests

- Update E2E tests: announcements, auth, auth-business-flow, full-route-regression, grades, navigation, smoke-auth, teacher-web-test

- Update integration tests: api-ai-chat, api-onboarding-complete, api-onboarding-status, proxy-guard, integration setup

- Update visual regression tests: admin-dashboard, homepage, student-dashboard, teacher-dashboard, visual config, helpers

- Update webapp tests: admin, parent, student full tests and debug scripts

- Add new webapp tests: announcements_messages, settings_profile, debug scripts

- Add webtest directory with test plans, screenshots, and diagnostic scripts

tests/webapp/debug_teacher_msg.py

@@ -0,0 +1,56 @@
+"""调试 teacher 发送消息"""
+from playwright.sync_api import sync_playwright
+import re
+
+BASE_URL = "http://localhost:3000"
+
+with sync_playwright() as p:
+    browser = p.chromium.launch(headless=True)
+    context = browser.new_context(viewport={"width": 1440, "height": 900}, locale="zh-CN")
+    page = context.new_page()
+
+    # 登录 teacher
+    page.goto(f"{BASE_URL}/login", timeout=30000)
+    page.wait_for_load_state("networkidle", timeout=15000)
+    page.locator('input[name="email"]').fill("t_chinese_1@xiaoxue.edu.cn")
+    page.locator('input[name="password"]').fill("123456")
+    login_btn = page.get_by_role("button", name=re.compile(r"Sign In with Email", re.I))
+    login_btn.click()
+    page.wait_for_timeout(3000)
+    page.wait_for_load_state("networkidle", timeout=15000)
+    print(f"登录后 URL: {page.url}")
+
+    # 访问撰写页面
+    print("\n访问 /messages/compose...")
+    page.goto(f"{BASE_URL}/messages/compose", timeout=30000)
+    page.wait_for_load_state("networkidle", timeout=15000)
+    page.wait_for_timeout(2000)
+
+    # 检查页面内容
+    body = page.locator("body").text_content()
+    print(f"页面内容 (前 1000 字符):")
+    print(body[:1000] if body else "(空)")
+
+    # 检查收件人选择器
+    print("\n检查收件人选择器...")
+    select_trigger = page.locator('button[role="combobox"]').first
+    print(f"button[role=combobox] count: {page.locator('button[role=\"combobox\"]').count()}")
+    print(f"[role=combobox] count: {page.locator('[role=\"combobox\"]').count()}")
+
+    # 检查所有 button 元素
+    buttons = page.locator("button").all()
+    print(f"\n页面按钮数: {len(buttons)}")
+    for i, btn in enumerate(buttons[:10]):
+        try:
+            text = btn.text_content()
+            role = btn.get_attribute("role")
+            type_ = btn.get_attribute("type")
+            print(f"  button[{i}]: role={role}, type={type_}, text={text[:50] if text else '(空)'}")
+        except Exception:
+            pass
+
+    # 截图
+    page.screenshot(path="tests/webapp/screenshots/announcements_messages/debug_teacher_compose.png", full_page=True)
+    print("\n截图已保存")
+
+    browser.close()