chore(EUDPA-301): prune redundant tests

[martyn-esynergy]

Jira: https://eaflood.atlassian.net/browse/EUDPA-301

Trim redundant Playwright E2E tests

Removes tests whose assertions are already proven by existing frontend/admin
unit tests, verified individually against current source before removal.

Removed: 48 of 280 tests (17%), for three common reasons:

• Validation error messages already asserted by a schema/controller test (22)
• Native HTML/browser behaviour — radio defaults, checkbox exclusivity,
  maxlength — not application logic (16)
• Status-conditional rendering, option catalogues, and default-state content
  already asserted by a mocked controller test (10)

Also in this PR:

• 3 tests added (features/validation-wiring.spec.ts) — one canary per
  validation pattern (dropdown/radio-group/checkbox), replacing dozens of
  near-identical per-page duplicates while still proving the pipeline renders
  end-to-end in a browser
• 5 tests kept and marked // Deliberate duplicate: ... — each duplicates
  covered logic but is the only remaining proof real backend data renders
  correctly live, not just via a mock
• 24 tests marked // TODO: naming a specific coverage gap — closing each
  means adding a schema/controller test in trade-imports-animals-frontend,
  not this repo

Net suite size (features/journeys/pages only, excludes a11y/visual): 280 → 235.

[github-actions]

✅ Workspace E2E Tests: success

📊 Playwright Report
🔗 Workflow Run