Add QA test outputs, build scripts, and Dockerfile validation

- Created `qa-test-output-after-fix.txt` and `qa-test-output.txt` to log results of certificate page authentication tests.
- Added `build.sh` for deterministic backend builds in CI, utilizing `go list` for efficiency.
- Introduced `codeql_scan.sh` for CodeQL database creation and analysis for Go and JavaScript/TypeScript.
- Implemented `dockerfile_check.sh` to validate Dockerfiles for base image and package manager mismatches.
- Added `sourcery_precommit_wrapper.sh` to facilitate Sourcery CLI usage in pre-commit hooks.

frontend/src/utils/cn.ts

@@ -0,0 +1,6 @@
+import { type ClassValue, clsx } from 'clsx'
+import { twMerge } from 'tailwind-merge'
+
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs))
+}