Add Gitea CI/CD pipeline for beta and prod

scripts/ci_backend_quality_gate.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$repo_root"
+
+python_bin="${PYTHON_BIN:-python3}"
+
+echo "Installing backend Python requirements"
+"$python_bin" -m pip install -r backend/requirements.txt
+
+echo "Running Python dependency integrity check"
+"$python_bin" -m pip check
+
+echo "Running backend unit tests"
+"$python_bin" -m unittest discover -s backend/tests -p "test_*.py" -v
+
+echo "Backend quality gate passed"