🛡️ Sentinel: Add Trusted Types to CSP

[keough99]

🚨 Severity: ENHANCEMENT
💡 Vulnerability: The application lacked Trusted Types enforcement, a defense-in-depth measure that blocks DOM-based XSS by disabling unsafe DOM sinks (e.g., innerHTML).
🎯 Impact: Prevents future code or third-party scripts from introducing DOM XSS vulnerabilities via string assignments to execution sinks.
🔧 Fix: Added require-trusted-types-for 'script'; trusted-types 'none'; to the Content-Security-Policy <meta> tags across all HTML files.
✅ Verification: Verify all automated tests pass, the site functions normally, and no CSP violation errors appear in the console.

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PR created automatically by Jules for task 11473765276609367673 started by @keough99

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