🛡️ Sentinel: [HIGH] Fix SSRF via opaque URL bypass in CLI executor

[rschumann]

🚨 Severity: HIGH
💡 Vulnerability: The executeRemote function was vulnerable to SSRF. It validated the scheme and host, but reconstructed the URL by copying the parsed url.URL struct by value and only modifying the Path. If an attacker provided an opaque URL (e.g., http:example.com/...), the String() method would prioritize the Opaque field, bypassing the path constraint.
🎯 Impact: An attacker could bypass routing constraints and potentially perform server-side request forgery (SSRF) against internal services or arbitrary external hosts.
🔧 Fix: Replaced the struct copy with an explicit url.URL{} struct literal instantiation, extracting only the safe fields (Scheme, Host, User, RawQuery) and applying the path constraint securely.
✅ Verification: Verified by generating test scripts mimicking opaque URLs before and after the fix, and confirming resolution via gosec scanner.

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PR created automatically by Jules for task 5820898506683009800 started by @rschumann

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