fix: Exclude demo_security_complete.py from detect-secrets

Demo file contains intentional example secrets for security testing.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: 2 people

.pre-commit-config.yaml

@@ -63,6 +63,7 @@ repos:
             tests/test_secure_memdocs\.py$|
             empathy_llm_toolkit/security/secrets_detector\.py$|
             empathy_llm_toolkit/security/secure_memdocs_example\.py$|
+            demo_security_complete\.py$|
             anthropic-cookbook/
           )