Update security policy with reporting guidelines

[akarnokd]

Added warnings about reporting issues and AI-related exploits.

[github-actions]

🐷 TruffleHog + Entropy Beauty Scan

Average entropy of changed code: 4.613 bits/char
Verdict: ✅ Mid-4 beauty detected (thoughtful human code!)

Changed files entropy:

SECURITY.md: 4.613

✅ No secrets or suspicious high-entropy strings found.

Mid-4 beauty heuristic in action — powered by our entropy chats! 😊

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.63%. Comparing base (a9754bf) to head (7d6e0cb).
⚠️ Report is 1 commits behind head on 4.x.

Additional details and impacted files

@@             Coverage Diff              @@
##                4.x    #8284      +/-   ##
============================================
+ Coverage     98.61%   98.63%   +0.02%     
+ Complexity     7149     7148       -1     
============================================
  Files           824      824              
  Lines         50784    50784              
  Branches       6907     6907              
============================================
+ Hits          50080    50093      +13     
+ Misses          480      476       -4     
+ Partials        224      215       -9     

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