Fix admin CSS not loading and quirks mode issues

Fixed multiple issues in admin panel:

1. CSS path: modern-normalize.css → modern-normalize.min.css
   (File is actually named .min.css)

2. Icon path: assets/icon.svg → /assets/admin_favicon.svg
   (Was relative, now absolute; correct filename)

3. Navigation: /admin/list.php → /admin/
   (list.php was renamed to index.php)

4. Short PHP tags: <? → <?php
   (Better compatibility, some servers don't enable short_open_tag)

5. Quirks mode warning was due to CSS not loading, not DOCTYPE
   (DOCTYPE was already present)

Files modified:
- public/admin/inc/head.php (main fixes)
- public/admin/index.php (short tags)
- public/admin/add.php (short tags)
- public/admin/import.php (short tags)

Need to redeploy for production: just deploy

scripts/manage-admin-user.sh

@@ -0,0 +1,199 @@
+#!/bin/bash
+# Manage admin users for Post-ERG nginx basic authentication
+
+set -e
+
+# Colors
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+BLUE='\033[0;34m'
+NC='\033[0m'
+
+PASSWORD_FILE="/etc/nginx/.htpasswd-posterg"
+
+# Check if running as root
+if [ "$EUID" -ne 0 ]; then
+    echo -e "${RED}Error: This script must be run as root (use sudo)${NC}"
+    exit 1
+fi
+
+# Check if htpasswd is available
+if ! command -v htpasswd &>/dev/null; then
+    echo -e "${YELLOW}Installing apache2-utils...${NC}"
+    apt-get update -qq
+    apt-get install -y apache2-utils
+fi
+
+show_menu() {
+    echo ""
+    echo -e "${BLUE}════════════════════════════════════════${NC}"
+    echo -e "${BLUE}  Post-ERG Admin User Management${NC}"
+    echo -e "${BLUE}════════════════════════════════════════${NC}"
+    echo ""
+    echo "1. List all users"
+    echo "2. Add new user"
+    echo "3. Change user password"
+    echo "4. Delete user"
+    echo "5. Reset all (create new password file)"
+    echo "6. Exit"
+    echo ""
+    echo -n "Choose an option [1-6]: "
+}
+
+list_users() {
+    echo ""
+    if [ ! -f "$PASSWORD_FILE" ]; then
+        echo -e "${YELLOW}No password file found.${NC}"
+        return
+    fi
+
+    echo -e "${GREEN}Current admin users:${NC}"
+    echo "────────────────────────"
+    cut -d: -f1 "$PASSWORD_FILE" | nl
+    echo ""
+}
+
+add_user() {
+    echo ""
+    echo -n "Enter new username: "
+    read -r USERNAME
+
+    if [ -z "$USERNAME" ]; then
+        echo -e "${RED}Username cannot be empty${NC}"
+        return
+    fi
+
+    # Check if user already exists
+    if [ -f "$PASSWORD_FILE" ] && grep -q "^${USERNAME}:" "$PASSWORD_FILE"; then
+        echo -e "${YELLOW}User '$USERNAME' already exists. Use option 3 to change password.${NC}"
+        return
+    fi
+
+    # Add user (use -c only if file doesn't exist)
+    if [ ! -f "$PASSWORD_FILE" ]; then
+        htpasswd -c "$PASSWORD_FILE" "$USERNAME"
+    else
+        htpasswd "$PASSWORD_FILE" "$USERNAME"
+    fi
+
+    echo -e "${GREEN}✓ User '$USERNAME' added successfully${NC}"
+}
+
+change_password() {
+    list_users
+    echo -n "Enter username to change password: "
+    read -r USERNAME
+
+    if [ -z "$USERNAME" ]; then
+        echo -e "${RED}Username cannot be empty${NC}"
+        return
+    fi
+
+    if [ ! -f "$PASSWORD_FILE" ]; then
+        echo -e "${RED}Password file not found${NC}"
+        return
+    fi
+
+    if ! grep -q "^${USERNAME}:" "$PASSWORD_FILE"; then
+        echo -e "${RED}User '$USERNAME' not found${NC}"
+        return
+    fi
+
+    htpasswd "$PASSWORD_FILE" "$USERNAME"
+    echo -e "${GREEN}✓ Password changed for user '$USERNAME'${NC}"
+}
+
+delete_user() {
+    list_users
+    echo -n "Enter username to delete: "
+    read -r USERNAME
+
+    if [ -z "$USERNAME" ]; then
+        echo -e "${RED}Username cannot be empty${NC}"
+        return
+    fi
+
+    if [ ! -f "$PASSWORD_FILE" ]; then
+        echo -e "${RED}Password file not found${NC}"
+        return
+    fi
+
+    if ! grep -q "^${USERNAME}:" "$PASSWORD_FILE"; then
+        echo -e "${RED}User '$USERNAME' not found${NC}"
+        return
+    fi
+
+    echo -n "Are you sure you want to delete user '$USERNAME'? [y/N] "
+    read -r CONFIRM
+
+    if [ "$CONFIRM" = "y" ] || [ "$CONFIRM" = "Y" ]; then
+        htpasswd -D "$PASSWORD_FILE" "$USERNAME"
+        echo -e "${GREEN}✓ User '$USERNAME' deleted${NC}"
+    else
+        echo "Cancelled"
+    fi
+}
+
+reset_all() {
+    echo ""
+    echo -e "${YELLOW}WARNING: This will delete ALL existing users!${NC}"
+    echo -n "Are you sure? [y/N] "
+    read -r CONFIRM
+
+    if [ "$CONFIRM" != "y" ] && [ "$CONFIRM" != "Y" ]; then
+        echo "Cancelled"
+        return
+    fi
+
+    # Backup existing file
+    if [ -f "$PASSWORD_FILE" ]; then
+        BACKUP="${PASSWORD_FILE}.backup.$(date +%Y%m%d_%H%M%S)"
+        cp "$PASSWORD_FILE" "$BACKUP"
+        echo -e "${GREEN}✓ Backed up to: $BACKUP${NC}"
+    fi
+
+    echo ""
+    echo -n "Enter new username: "
+    read -r USERNAME
+
+    if [ -z "$USERNAME" ]; then
+        echo -e "${RED}Username cannot be empty${NC}"
+        return
+    fi
+
+    htpasswd -c "$PASSWORD_FILE" "$USERNAME"
+    echo -e "${GREEN}✓ Password file reset with user '$USERNAME'${NC}"
+}
+
+# Main loop
+while true; do
+    show_menu
+    read -r CHOICE
+
+    case $CHOICE in
+    1)
+        list_users
+        ;;
+    2)
+        add_user
+        ;;
+    3)
+        change_password
+        ;;
+    4)
+        delete_user
+        ;;
+    5)
+        reset_all
+        ;;
+    6)
+        echo ""
+        echo "Goodbye!"
+        exit 0
+        ;;
+    *)
+        echo -e "${RED}Invalid option${NC}"
+        ;;
+    esac
+done