feat: Add password generation and testing scripts

- Add generate-password.js for Node.js password hash generation
- Add generate-password-docker.sh for Docker-based generation
- Add test-password.sh to verify password against current hash

These scripts help users generate correct bcrypt hashes for the
ADMIN_PASSWORD_HASH environment variable.

Usage:
- Generate new hash: ./scripts/generate-password-docker.sh
- Test current password: ./scripts/test-password.sh

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/generate-password-docker.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+echo "================================="
+echo "MinIO WebUI Password Generator"
+echo "================================="
+echo ""
+read -s -p "Enter password: " PASSWORD
+echo ""
+
+if [ -z "$PASSWORD" ] || [ ${#PASSWORD} -lt 8 ]; then
+    echo "Error: Password must be at least 8 characters long."
+    exit 1
+fi
+
+echo ""
+echo "Generating password hash..."
+
+# Use the backend container to generate the hash
+HASH=$(docker run --rm -it node:20-alpine sh -c "
+    npm install bcrypt >/dev/null 2>&1 && \
+    node -e \"
+        const bcrypt = require('bcrypt');
+        bcrypt.hash('$PASSWORD', 12).then(hash => console.log(hash));
+    \"
+" | tr -d '\r')
+
+echo ""
+echo "================================="
+echo "Password Hash Generated:"
+echo "================================="
+echo ""
+echo "$HASH"
+echo ""
+echo "Add this to your .env file:"
+echo "ADMIN_PASSWORD_HASH=$HASH"
+echo ""
+echo "================================="