chore: refactor agent configurations and update testing instructions

- Updated QA Security agent to use GPT-5.2-Codex and expanded toolset for enhanced functionality.
- Revised Supervisor agent to utilize GPT-5.2-Codex and improved toolset for code review processes.
- Modified architecture instructions to specify running Playwright tests with Firefox.
- Adjusted copilot instructions to run Playwright tests with Firefox as the default browser.
- Created documentation for coding best practices to ensure consistency and quality in project documentation.
- Established HTML/CSS style color guide to maintain accessible and professional design standards.
- Updated Playwright TypeScript instructions to reflect the change in default browser to Firefox.
- Enhanced testing instructions to clarify integration testing processes and default browser settings.
- Updated integration test scripts to align with CI workflows and improve clarity in execution.
- Created new integration test scripts for Cerberus, rate limiting, and WAF functionalities.
- Adjusted E2E testing scripts to default to Firefox and updated documentation accordingly.
- Modified GitHub Actions workflow to run the comprehensive integration test suite.

.github/instructions/testing.instructions.md

@@ -35,6 +35,7 @@ This step:
 - Ensure forms submit correctly
 - Check navigation and page rendering
 - **Port: 8080 (Charon Management Interface)**
+- **Default Browser: Firefox** (provides best cross-browser compatibility baseline)
 
 **Integration Tests (Middleware Enforcement):**
 - Test Cerberus security module enforcement
@@ -61,7 +62,7 @@ For general integration testing without coverage:
 
 ```bash
 # Against Docker container (default)
-npx playwright test --project=chromium --project=firefox --project=webkit
+cd /projects/Charon npx playwright test --project=firefox --project=firefox --project=webkit
 
 # With explicit base URL
 PLAYWRIGHT_BASE_URL=http://localhost:8080 npx playwright test --project=chromium --project=firefox --project=webkit