refactor(tests): restructure into layered POM architecture with Allure reporting

- Split framework into core/ (config, logger, db, driver factories, screenshot,
  allure integration) and pages/ (PO layer: base/admin/driver); flatten test
  files per platform (web/admin, app/driver_android, cross_end)
- Slim root conftest.py 656 -> ~100 lines: drop inline CN HTML report, add
  Allure severity mapping (p0/p1/p2 -> blocker/normal/minor) and
  environment.properties; support both tests.*-prefixed and bare imports
- Preserve TC-D2S-001/002 cross-end E2E cases with business logic unchanged,
  add allure epic/feature/story/step annotations
- Deduplicate: single makereport hook, shared failure-screenshot helpers,
  single SCREENSHOTS_DIR constant; deterministic auth-state role loading
- Move DB credentials from db_helper.py into test_config.yaml (database section)
- Move pytest.ini to repo root; switch reporting to allure-pytest
  (drop pytest-html/junitxml); update requirements.txt accordingly
- Delete deprecated scaffolding: test_freight_full_flow + 6 stale page
  objects, iOS/shipper empty shells, dead utils
- Fix flaky vxe-table action-row wait: wait for a visible td instead of
  hidden placeholder rows (fixed shipper-payment timeouts)
- Verified end-to-end against live env: both E2E cases pass (2 passed 3m12s);
  run artifacts (logs/screenshots/allure) included per repo convention

output/allure-results/539412a0-6394-428a-8505-5fa2c591d711-container.json

@@ -0,0 +1 @@
+{"uuid": "76bab243-771c-4cff-9547-e7e0fa175cd1", "children": ["77514abb-865c-424d-801d-65edba8090fb"], "befores": [{"name": "app_driver", "status": "passed", "start": 1786934002251, "stop": 1786934007627}], "afters": [{"name": "app_driver::1", "status": "passed", "start": 1786934101422, "stop": 1786934101706}, {"name": "app_driver::<lambda>", "start": 1786934101706}], "start": 1786934002251, "stop": 1786934101706}