Fix: Rename directory to remove & character causing shell issues

Renamed ebook_backend&admin_panel to ebook_backend_admin_panel
  The & character was being interpreted by shell as background
  process operator, causing 'Dockerfile not found' errors in Coolify.

ebook_backend_admin_panel/Dockerfile

@@ -0,0 +1,70 @@
+# Multi-stage build pre optimalizáciu veľkosti obrazu
+FROM python:3.11-slim as builder
+
+# Nastavenie working directory
+WORKDIR /app
+
+# Inštalácia build dependencies
+RUN apt-get update && apt-get install -y \
+    gcc \
+    postgresql-client \
+    libpq-dev \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
+
+# Kopírovanie requirements
+COPY requirements.txt .
+
+# Inštalácia Python dependencies do /opt/venv
+RUN python -m venv /opt/venv
+ENV PATH="/opt/venv/bin:$PATH"
+RUN pip install --no-cache-dir --upgrade pip && \
+    pip install --no-cache-dir -r requirements.txt
+
+# Production stage
+FROM python:3.11-slim
+
+# Nastavenie environment variables
+ENV PYTHONUNBUFFERED=1 \
+    PYTHONDONTWRITEBYTECODE=1 \
+    PATH="/opt/venv/bin:$PATH"
+
+# Inštalácia runtime dependencies
+RUN apt-get update && apt-get install -y \
+    postgresql-client \
+    libpq-dev \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
+
+# Vytvorenie non-root user pre bezpečnosť
+RUN useradd -m -u 1000 appuser
+
+# Nastavenie working directory
+WORKDIR /app
+
+# Kopírovanie Python virtual environment z builder stage
+COPY --from=builder /opt/venv /opt/venv
+
+# Kopírovanie aplikačných súborov
+COPY --chown=appuser:appuser . .
+
+# Vytvorenie potrebných adresárov
+RUN mkdir -p /app/admin-backend/logs \
+    /app/admin-backend/translationfile \
+    && chown -R appuser:appuser /app
+
+# Prepnutie na non-root user
+USER appuser
+
+# Expose port
+EXPOSE 8000
+
+# Healthcheck
+HEALTHCHECK --interval=30s --timeout=10s --start-period=40s --retries=3 \
+    CMD curl -f http://localhost:8000/health || exit 1
+
+# Spustenie aplikácie
+WORKDIR /app/admin-backend
+
+# Použijeme shell form aby sme mohli spustiť init_db.py a potom uvicorn
+CMD ["/bin/sh", "-c", "python init_db.py && uvicorn main:app --host 0.0.0.0 --port 8000 --workers 4"]