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/components/ui/Button.tsx

@@ -0,0 +1,55 @@
+import { ButtonHTMLAttributes, ReactNode } from 'react'
+import { clsx } from 'clsx'
+
+interface ButtonProps extends ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: 'primary' | 'secondary' | 'danger' | 'ghost'
+  size?: 'sm' | 'md' | 'lg'
+  isLoading?: boolean
+  children: ReactNode
+}
+
+export function Button({
+  variant = 'primary',
+  size = 'md',
+  isLoading = false,
+  className,
+  children,
+  disabled,
+  ...props
+}: ButtonProps) {
+  const baseStyles = 'inline-flex items-center justify-center rounded-lg font-medium transition-colors focus:outline-none focus:ring-2 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed'
+
+  const variants = {
+    primary: 'bg-blue-600 text-white hover:bg-blue-700 focus:ring-blue-500',
+    secondary: 'bg-gray-700 text-white hover:bg-gray-600 focus:ring-gray-500',
+    danger: 'bg-red-600 text-white hover:bg-red-700 focus:ring-red-500',
+    ghost: 'text-gray-400 hover:text-white hover:bg-gray-800 focus:ring-gray-500',
+  }
+
+  const sizes = {
+    sm: 'px-3 py-1.5 text-sm',
+    md: 'px-4 py-2 text-sm',
+    lg: 'px-6 py-3 text-base',
+  }
+
+  return (
+    <button
+      className={clsx(
+        baseStyles,
+        variants[variant],
+        sizes[size],
+        className
+      )}
+      disabled={disabled || isLoading}
+      {...props}
+    >
+      {isLoading && (
+        <svg className="animate-spin -ml-1 mr-2 h-4 w-4 text-current" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24">
+          <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4"></circle>
+          <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
+        </svg>
+      )}
+      {children}
+    </button>
+  )
+}