chore: Revamp frontend test iteration plan and documentation

- Updated design documentation to reflect the new Playwright-first approach for frontend testing, including orchestration flow and runbook notes.
- Revised requirements to align with the new frontend test iteration strategy, emphasizing E2E environment management and coverage thresholds.
- Expanded tasks to outline phased implementation for frontend testing, including Playwright E2E baseline, backend triage, and coverage validation.
- Enhanced QA report to capture frontend coverage failures and type errors, with detailed remediation steps for accessibility compliance.
- Created new security validation and accessibility remediation reports for CrowdSec configuration, addressing identified issues and implementing fixes.
- Adjusted package.json scripts to prioritize Firefox for Playwright tests.
- Added canonical links for requirements and tasks documentation.

docs/development/running-e2e.md

@@ -37,6 +37,10 @@ This document explains how to run Playwright tests using a real browser (headed)
    ```bash
    .github/skills/scripts/skill-runner.sh docker-rebuild-e2e
    ```
+  If you need a clean rebuild after integration alignment changes:
+  ```bash
+  .github/skills/scripts/skill-runner.sh docker-rebuild-e2e --clean --no-cache
+  ```
 2. Run the UI against the container (you still need an X server on your host):
    ```bash
    PLAYWRIGHT_BASE_URL=http://localhost:8080 npm run e2e:ui:headless-server