feat(workflow): add complexity check for Go codebase

This commit introduces a new GitHub Actions workflow to automatically
check the complexity of Go functions using gocyclo. The workflow
triggers on pushes and pull requests to the main branch. It ensures
that any function exceeding a complexity threshold of 20 is flagged,
helping maintain code quality and readability.

.github/workflows/complecity-check.yml

@@ -0,0 +1,28 @@
+name: Complexity Check
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  complexity:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+
+      - name: Install gocyclo
+        run: go install github.com/fzipp/gocyclo/cmd/gocyclo@latest
+
+      - name: Run gocyclo
+        run: gocyclo -over 20 . || exit 1
+
+      - name: Fail on high complexity
+        if: failure()
+        run: echo "One or more functions exceed the permissible complexity threshold of 20."