… add coverage

Wire campaign preview Playwright tests into the contact center e2e runner
and add 9 new tests covering previously untested component behavior.

Infrastructure:
- constants.ts: add CAMPAIGN_TEST_IDS with all 21 data-testid values from
  the CampaignTask component tree (task, list item, title, phone, actions,
  buttons, expanded area, popover, countdown, global variables, error dialog)
- test-manager.ts: add setupForCampaignPreview() — single agent, desktop
  login, console logging (campaign tests inject mock tasks via page.evaluate)
- test-data.ts: add SET_10 with TEST_SUITE pointing to
  campaign-preview-tests.spec.ts so playwright.config.ts auto-discovers it

Utility enhancement:
- campaignPreviewUtils.ts: extend stubCampaignPreviewActions to support
  'cancel' failAction (stubs task.end() to reject), add cancel tracking to
  getCampaignActionCounts return type

New test coverage (9 tests across 6 describe blocks):
- Cancel Error: cancel failure shows error dialog with correct title,
  dismiss re-enables cancel button
- Button Disabled Combinations: both skip and remove disabled simultaneously,
  accept remains enabled
- Countdown Display: countdown timer renders when timeout timestamp is set
- Fallback Title: empty customer name falls back to ANI as title, phone
  subtitle hidden when it equals the title
- Error Dialog Content: verifies correct error title text for accept, skip,
  and remove failures (3 tests)
- Re-offer After Skip: simulated new contact (changed timeout) resets all
  buttons to enabled state

Total campaign preview test count: 22 existing + 9 new = 31 tests

…d of prototype

refreshTaskList is a bound class field (own property), not a prototype
method. The previous restoreRefreshTaskList read from the prototype
where it was always undefined, making the restore a silent no-op.

Now stubRefreshTaskList saves the original on window before overwriting,
and restoreRefreshTaskList restores from that saved reference.