CI/CD hardening: lint, secret scan, coverage gate, auto CVE-fix PRs, GHCR + GitHub mirror publishing (#32)

- release changelog: commits rendered as description (link), divider lines dropped
- gitleaks secret scan and hadolint on every push/PR
- ruff lint/format gate (Python repos) with a pytest --cov-fail-under gate
- scheduled CRITICAL Trivy failures attempt an apk upgrade rebuild and open a follow-up PR if it clears the finding, instead of just failing red
- images also published to ghcr.io/djeex/<repo>
- a matching GitHub Release is created on the GitHub mirror, with a notice pointing back to this repo as the source of truth

app/main.py

@@ -1,17 +1,20 @@
-import time
 import logging
 import signal
 import sys
-from gpu_checker import check_rtx_50_founders
+import time
+
 from env_config import REFRESH_TIME
+from gpu_checker import check_rtx_50_founders
+
 
 # Signal handler function
 def handle_exit(signum, frame):
     logging.info(f"🛑 Received signal {signum}. Exiting gracefully...")
     sys.exit(0)
 
+
 # Register signal handlers
-signal.signal(signal.SIGINT, handle_exit)   # Ctrl+C
+signal.signal(signal.SIGINT, handle_exit)  # Ctrl+C
 signal.signal(signal.SIGTERM, handle_exit)  # docker stop / kill -15
 
 if __name__ == "__main__":
@@ -24,4 +27,3 @@ if __name__ == "__main__":
     except KeyboardInterrupt:
         logging.info("🛑 Script interrupted by user (KeyboardInterrupt). Exiting gracefully.")
         sys.exit(0)
-