🛡️ Sentinel: Add Trusted Types to Content Security Policy

[keough99]

🚨 Severity: ENHANCEMENT
💡 Vulnerability: While active scripts do not use unsafe DOM sinks, unused vendor scripts in /assets contain innerHTML usages. If accidentally loaded or if future code introduces sinks, the site could be exposed to DOM-based XSS.
🎯 Impact: Completely neutralizes DOM-based XSS attacks by instructing the browser to block all string-to-DOM sink assignments.
🔧 Fix: Enhanced the Content-Security-Policy <meta> tag across all HTML pages by adding require-trusted-types-for 'script'; trusted-types 'none';.
✅ Verification: Start a local server, navigate to any page, and verify via Developer Tools that Trusted Types are enforced and no functionality is broken.

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PR created automatically by Jules for task 14118620678270979432 started by @keough99

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