feat: add self-service profile page with manage navigation

Add /manage/profile page where authenticated users can view and edit
their OIDC profile fields (given_name, family_name, preferred_username,
email, phone_number, picture, locale).

- Create manage/base.html with tab-style nav for Profile/Credentials
- Update credentials.html to extend manage/base.html
- Add GET/POST routes with server-side validation
- Add input styling for tel and url input types
- Add profile test user with pre-filled data in setup_db.py
- Add 19 E2E tests covering structure, navigation, updates, validation
- All 76 E2E tests and 172 Python tests pass

tests/e2e/setup_db.py

@@ -79,6 +79,27 @@ async def seed() -> None:
     await magic_link_service.mark_used(expired_link.token)
     result["used_token"] = expired_link.token
 
+    # 5. Create a user with profile data for profile management tests
+    profile_user = User(
+        userid="test-user-04",
+        username="profileuser",
+        given_name="Alice",
+        family_name="Smith",
+        preferred_username="asmith",
+        email="alice@example.com",
+        phone_number="+1234567890",
+        picture="https://example.com/alice.jpg",
+        locale="en",
+        groups=["users"],
+    )
+    await user_repo.create(profile_user)
+    profile_password_hash = password_service.hash("profilepass123")
+    await cred_repo.create_password(
+        PasswordCredential(user_id=profile_user.userid, password_hash=profile_password_hash)
+    )
+    result["profile_username"] = "profileuser"
+    result["profile_password"] = "profilepass123"
+
     await db.commit()
     await db.close()
     print(json.dumps(result))