fix: resolve Playwright strict mode violations in Jellyfin invite tests

Fixed two E2E test failures caused by Playwright strict mode violations:

1. 'admin can access invites page': Added `exact: true` to heading selector
   to match only "Invites" heading, not "No invites yet"

2. 'admin can open create invite modal': Changed from `getByText()` to
   `getByRole('heading')` to specifically target the modal heading instead
   of matching both the heading and submit button

Both tests were timing out due to locators resolving to multiple elements.
The fixes ensure selectors uniquely identify single elements following
Playwright best practices.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>

Author: mchestr

e2e/jellyfin-invite.spec.ts

@@ -127,7 +127,7 @@ test.describe('Jellyfin Invite Flow', () => {
       await adminPage.locator('aside').getByTestId('admin-nav-invites').first().click();
       await waitForLoadingGone(adminPage);
 
-      await expect(adminPage.getByRole('heading', { name: 'Invites' })).toBeVisible({ timeout: WAIT_TIMEOUTS.ADMIN_CONTENT });
+      await expect(adminPage.getByRole('heading', { name: 'Invites', exact: true })).toBeVisible({ timeout: WAIT_TIMEOUTS.ADMIN_CONTENT });
       await expect(adminPage.getByTestId('generate-invite-button')).toBeVisible();
     });
 
@@ -139,7 +139,7 @@ test.describe('Jellyfin Invite Flow', () => {
 
       // Modal should appear
       await expect(adminPage.getByRole('dialog')).toBeVisible({ timeout: WAIT_TIMEOUTS.DIALOG_APPEAR });
-      await expect(adminPage.getByText('Create Invite')).toBeVisible();
+      await expect(adminPage.getByRole('heading', { name: 'Create Invite' })).toBeVisible();
     });
 
     test('admin can create a Jellyfin invite via database', async ({ adminPage }) => {