fix(web): use oninput binding in EditSession for reliable E2E interaction

Blazor Server's default change-event binding races with Playwright fills,
causing input values to revert before the form submits. Switch Title,
JoinLink and MaxPlayers to @bind-Value:event=oninput so the model stays
in sync while the test types.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/GmRelay.Web/Components/Pages/EditSession.razor

@@ -36,7 +36,7 @@
             <EditForm Model="@model" OnValidSubmit="HandleSubmit">
                 <div class="gm-form-group">
                     <label class="gm-form-label">Название игры</label>
-                    <InputText @bind-Value="model.Title" class="gm-form-control" placeholder="например, D&D 5e: Dragon's Hoard" />
+                    <InputText @bind-Value="model.Title" @bind-Value:event="oninput" class="gm-form-control" placeholder="например, D&D 5e: Dragon's Hoard" />
                     <div class="gm-form-hint">Изменение этого поля обновит все сессии в одной группе.</div>
                 </div>
 
@@ -48,12 +48,12 @@
 
                 <div class="gm-form-group">
                     <label class="gm-form-label">Ссылка для подключения</label>
-                    <InputText @bind-Value="model.JoinLink" class="gm-form-control" placeholder="Ссылка на Discord или VTT" />
+                    <InputText @bind-Value="model.JoinLink" @bind-Value:event="oninput" class="gm-form-control" placeholder="Ссылка на Discord или VTT" />
                 </div>
 
                 <div class="gm-form-group">
                     <label class="gm-form-label">Лимит мест</label>
-                    <InputNumber @bind-Value="model.MaxPlayers" class="gm-form-control" min="1" placeholder="Без лимита" />
+                    <InputNumber @bind-Value="model.MaxPlayers" @bind-Value:event="oninput" class="gm-form-control" min="1" placeholder="Без лимита" />
                     <div class="gm-form-hint">Пустое значение означает запись без лимита. Если лимит заполнен, новые игроки попадут в лист ожидания.</div>
                 </div>
 

tests/e2e/dashboard/test_dashboard_auth_and_sessions.py

@@ -334,20 +334,44 @@ def test_dashboard_session_edit_flow() -> None:
             page.goto(f"{base_url}/session/edit/{session_id}")
             page.wait_for_selector("text=Редактирование сессии", timeout=15000)
 
+            def _fill_blazor_input(locator, value: str) -> None:
+                """Fill a Blazor-bound input, move focus out, and wait for the value to stick."""
+                locator.fill(value)
+                locator.press("Tab")
+                # Blazor Server round-trips on change; give it time to update the model
+                # and re-render before the next field is touched.
+                page.wait_for_timeout(500)
+                expect(locator).to_have_value(value)
+
             title_input = page.locator(".gm-form-group").filter(has_text="Название игры").locator("input").first
-            title_input.fill(updated_title)
+            _fill_blazor_input(title_input, updated_title)
 
             join_input = page.locator(".gm-form-group").filter(has_text="Ссылка для подключения").locator("input").first
-            join_input.fill(updated_join_link)
+            _fill_blazor_input(join_input, updated_join_link)
 
             max_players_input = page.locator(".gm-form-group").filter(has_text="Лимит мест").locator("input").first
-            max_players_input.fill("3")
+            _fill_blazor_input(max_players_input, "3")
+
+            # Verify the form actually received the new values before Blazor submits.
+            filled_title = title_input.input_value()
+            filled_join = join_input.input_value()
+            filled_max = max_players_input.input_value()
+            print(f"Edit form values before save: title={filled_title!r}, join={filled_join!r}, max={filled_max!r}")
 
             save_button = page.locator("button:has-text('Сохранить изменения')").first
             save_button.click()
 
             page.wait_for_url(f"{base_url}/group/{group_id}", timeout=15000)
-            page.wait_for_selector(f"text={updated_title}", timeout=15000)
+            try:
+                page.wait_for_selector(f"text={updated_title}", timeout=15000)
+            except Exception:
+                dump_path = "e2e_edit_group_debug.html"
+                with open(dump_path, "w", encoding="utf-8") as f:
+                    f.write(page.content())
+                print("URL after edit save:", page.url)
+                print(f"Group page HTML dumped to {dump_path}")
+                page.screenshot(path="e2e_edit_group_debug.png")
+                raise
             expect(page.locator(f"text={updated_title}").first).to_be_visible()
 
             db_session = _get_session_from_db(session_id)